abstracts: poster presentations for eurospine annual meeting 2013
TRANSCRIPT
ABSTRACTS
Abstracts: Poster Presentations for Eurospine Annual Meeting2013
ADULT THORACOLUMBAR SPINE, DEGENERATIVE
P1
INTERSPINOUS PROCESS IMPLANT APERIUS
PERCLID CAUSES WEAR OF THE SPINOUS
PROCESSES - EXPERIMENTAL STUDY
AND CLINICAL CASE REPORTS
Adad Baranto, Lars Ekstrom, Helena Brisby, Klas Halldin,
Jonas Hvannberg
Department of Orthopedics, Gothenburg, Sweden
Background: There are few biomechanical studies on interspinous
process implants but none that have investigated the amount of wear
caused to the spinous processes.
Purpose: To investigate the effect of repetitive loading of the interspi-
nosus implant Aperius on the spinous processes in a biomechanical
porcine model. We also present three clinical cases operated with Aperius
followed with X-rays and CT up to one year.
Study design: Biomechanical analysis of cyclic loading of lumbar
spinal segments operated with Aperius implants. Three patients
operated with Aperius are also presented.
Study sample: Eight lumbar segments from porcine were operated
in vitro with the interspinous process implants Aperius (6), and as
controls the interspinous implants X-Stop (1) and DIAM (1).
Methods: Four lumbar spines from 6 months old porcinis were
divided into eight segments, which received interspinous implants.
The segments were then exposed to 20.000 cyclical loads where after
the deformation (wear) of the segments was registered. The wear of
the spinous processes was measured in mm on the following CT-scan.
Additionally, three patients treated with interspinous implants were
followed between one and two years postoperatively. The wear of the
spinous processes on CT-scans or X-ray were presented together with
the clinical results.
Results: The mean maximal deformation of all specimens was 1.8 (SD
0.24) mm where the largest deformation occurred in the first quarter of the
loading (\ 5000 cycles). The mean wear of the spinous processes after
loading was 5.75 mm in the Aperius cases and 3.00 mm in the X-Stop
cases. No wear was found in the DIAM segment. Wear of the spinous
processes was detected in the clinical cases already after three months
postoperatively and interestingly two of the patients had recurrence of
their symptoms and planned for decompression surgery.
Conclusions: In an experimental biomechanical study under cyclical
loading the interspinous titanium implant Aperius causes significant
wear of the spinous processes. Also the X-Stop implant caused wear
of the spinous process. No wear was detected on the segment with an
implant made of silicon (DIAM). Wear of the spinous process is also
present in clinical cases already at three months post-operatively. The
clinical importance of these findings is still not clarified but indicates
that the material the implant is made of is of importance for the
clinical durability. Further clinical studies are needed.
P2
IS AUTOGENOUS BONE GRAFT REALLY
STRUCTURALLY INFERIOR TO A CAGE
IN INSTRUMENTED LUMBAR INTERBODY FUSIONS
Alexander Durst, Andrew Cook, Shaishav Bhagat, Am Rai,
Robert Crawford
Norfolk and Norwich Hospital, Norwich, UK
Objectives: We aimed to compare loss of disc fusion height in
patients undergoing a pedicle screw stabilised Posterior Lumbar
Interbody Fusion (PLIF) using local autogenous bone graft to those
using synthetic cages.
Methods: 99 patients underwent instrumented PLIF (one level or two
level) between2007 and 2011 at our tertiary spinal unit. 36 using bone graft
and 63 using a age. Loss of disc height was calculated by comparing post-
operative radiographs with those at a minimum of 6 months follow-up.
Results: In the graft group mean loss of height was 2.67 mm (95 %
CI 1.82-3.52) with a mean follow-up of 14.7 months. The mean in the
cage group 2.54 mm (95 % CI 1.94-3.14) with a mean follow-up of
18.2 months. There was no significant difference between the 2
groups (p = 0.798). Loss of disc fusion height was statistically
greater for men than women in both groups (p = 0.044).
Conclusion: Previous studies have suggested that use of bone graft
alone in instrumented PLIFs may result in loss of fusion height. We have
shown that a technique of packed bone graft with a block of bone placed
posteriorly in the disc space creates a mechanical construct providing
comparable structural support to that of a cage. This technique has
clear financial advantages in an era of spiralling spinal surgical costs.
P3
DEVELOPMENT AND FACE VALIDITY
OF CRITERIA FOR ASSESSING
THE APPROPRIATENESS OF SURGERY
FOR LUMBAR DEGENERATIVE
SPONDYLOLISTHESIS
Anne F Mannion, Valerie Pittet, Felix Steiger, Hans-Jurgen Becker,
John-Paul Vader, Francois Porchet, and the Zurich Appropriateness
of Spine Surgery (ZASS) Group
Spine Center, Schulthess Klinik, Zurich, Switzerland
123
Eur Spine J (2013) 22 (Suppl 5):S720–S766
DOI 10.1007/s00586-013-2947-6
Introduction: In spine surgery, treatment failures are often attributed
to poor patient selection and inappropriate treatment. However, for
many spinal disorders there is little consensus on the precise indica-
tions for surgery, and gold standards based on RCTs are lacking. We
addressed one such gap in the evidence-base by using the RAND
Appropriateness Method (RAM; detailed literature review and mod-
ified Delphi expert panel) to develop criteria for the appropriateness
of surgery (AoS) in lumbar degenerative spondylolisthesis (LDS).
Methods: Clinical scenarios were generated comprising combinations
of signs and symptoms in LDS and other relevant parameters
(‘‘variables’’). 12 multidisciplinary international experts rated each
scenario on a 9-point scale (1 highly inappropriate, 9 highly appro-
priate) with respect to doing decompression only, fusion, and
instrumented fusion. Surgery for each scenario was classified as
appropriate, inappropriate, or uncertain based on the median values
and disagreement in the ratings. Multiple regression was used to
examine: 1) the extent to which the different variables influenced the
median ratings in a logical way (‘‘face validity’’); 2) the variables
most strongly associated with ‘‘appropriate’’ scenarios.
Results: 744 hypothetical scenarios were generated; overall, surgery
(of some type) was appropriate in 27 %, uncertain in 41 % and inap-
propriate in 31 %. Frank panel disagreement was low (7 % scenarios).
90 % of the variance in median ratings was explained by the variables
neurogenic claudication, radicular pain, stenosis, LBP, yellow flags,
instability, neurological deficit, comorbidity, disability (each
p \ 0.05). Face validity was shown by the logical relationship between
each variable’s subcategories and the ratings, e.g., compared with no/
mild disability, having moderate or severe disability increased the
average ratings by 2.7 and 4.3 points, respectively. The three variables
most likely (p \ 0.0001) to be components of scenarios considered
‘‘appropriate’’ were: severe disability, no yellow flags, and severe
neurological deficit.
Conclusion: This is the first study to report AoS criteria for LDS
developed by a multidisciplinary international panel using a validated
method (RAM). The panel ratings followed logical clinical rationale,
indicating good face validity. The criteria should be evaluated for
predictive validity on a prospective basis to examine whether patients
treated ‘‘appropriately’’ do indeed have better clinical outcomes.
P4
VERTEBRAL RETROLISTHESIS
AND ANTEROLISTHESIS OF DEGENERATIVE
LUMBAR SPINE: THEIR DIFFERENT
CONTRIBUTIONS IN SPINE SAGITTAL BALANCE
BAO Hong-da, ZHU Feng, LIU Zhen, ZHU Ze-zhang, XU Lei-lei,
QIAO Jun, QIU Yong
Spine Surgery, Nanjing, China
Introduction: Lumbar instability is one of the common degenerative
changes of spine in which forwards slippage of one vertebral body on
another, known as spondylolisthesis or anterolisthesis, and backward
translational deformity, namely retrolisthesis, were included. In clinical
practice, retrolisthesis is considered as one of the compensatory
mechanisms of sagittal unbalance in aging spine. To the best of our
knowledge, however, few studies have focused on the contribution that
retrolisthesis made to sagittal balance. The objective of the present
study is to compare sagittal alignment between anterolisthesis and
retrolisthesis, as well as to elucidate their different contribution to
sagittal balance.
Methods: This study was a retrospective review of 26 retrolisthesis
patients (19 females and 7 males) and 20 anterolisthesis patients (3
males and 17 females). 17 of the retrolisthesis patients and 6 of the
anterolisthesis patients were associated with adult scoliosis. Long-
cassette standing upright radiographs were taken; Sagittal parameters
including sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar
lordosis (LL), the spinosacral angle (SSA), pelvic incidence (PI),
pelvic tilt (PT), sacral slope (SS) were measured through digital
analysis software. Independent samples t-tests were performed to
compare radiographic parameters between retrolisthesis group and
anterolisthesis group. Spinopelvic sagittal alignments in both groups
were also classified into four types defined by Roussouly et al.
Results: In the present study, PI, SS, LL, SVA in retrolisthesis group
were significantly smaller than those in anterolisthesis group
(p \ 0.05). In contrast, PT, TK and SSA were not different between
the two groups. Retrolisthesis patients were mostly classified into
Type 1 or 2 (low PI and SS), and patients with anterolisthesis tended
to be classified into Type 3 or 4 (high PI and SS).
Conclusion: The results confirmed that retrolisthesis permitted to limit
anterior translation of the axis of gravity since PT and TK were similar
in both groups. It is also hypothesized that low PI may contribute to
development and progression of different slip direction of vertebrae.
Keywords: Retrolisthesis, anterolisthesis, sagittal balance, pelvic
incidence, compensatory mechanism
P5
THE EFFECT OF THE LENGTH OF THE PEDICLE
SCREW FIXATION LEVEL FOR LUMBAR
DEGENERATIVE SPONDYLOLISTHESIS:
PRELIMINARY RESULTS OF ONE YEAR
FOLLOW-UP
Bora Gurer, Ahmet M. Sanli, Erhan Turkoglu, Hayri Kertmen,
Erdal R. Yilmaz, Zeki Sekerci
Ministry of Health, Diskapi Yildirim Beyazit Education and Research
Hospital, Neurosurgey Clinic, Ankara/Turkey, Ankara, Turkey
Introduction: Lumbar degenerative spondylolisthesis is a disease of
the older ages, and characterized by displacement of one vertebral body
over another due to disc degeneration and facet arthropathy, most
commonly combined with spinal canal stenosis at the affected levels.
The purpose of this study is to evaluate whether the length of the seg-
mental stabilization has any effect on quality of life, disability and pain.
Materials and methods: This retrospective study comprised 43 patients
who were operated due to lumbar degenerative spondylolisthesis. The
patients were divided into two groups by the length of the posterior sta-
bilization levels: Group I (short-segment group): operated for only two-
level posterior stabilization; Group II (long-segment group): operated for
three and four-level posterior stabilization. The medical outcomes study
36-Item short form general health survey, oswestry disability index and
visual analogue scale were used to analyze the outcome.
Results: It was clearly shown that, posterior segmental stabilization
increased the postoperative quality of health in the both groups, by all
parameters of Short Form -36 survey. Evermore in the group I, the dif-
ference between the preoperative and postoperative scores of the role
limitations due to physical health problems, bodily pain, general health
perceptions, social functioning, mental health, vitality and mental com-
ponent summary were better than group II, predisposing a better quality of
life results were obtained with short-segmental stabilization. Postoperative
Oswestry Disability Index and Visual Analogue Scale of the both groups
decreased postoperatively. The decrease of the Oswestry Disability Index
and Visual Analogue Scale was better in group I than group II.
Conclusions: Our study showed that both short- and long-segmental
posterior stabilization caused a significant better quality of health
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S721
123
results, disability scores and less pain scores postoperatively for the
lumbar degenerative spondylolisthesis. The most important result of
our study is that, short-segmental stabilization caused significantly
better Short Form-36 scores, Oswestry Disability Index and Visual
Analogue Scale.
P6
LACK OF PRECISION IN CODING LUMBAR DISC
PROLAPSE SIZE
Bruce S. Watson, Philip Nie, J.N. Alastair Gibson
Orthopaedic Surgery, Edinburgh, UK
Objective: Investigators assessing outcomes following lumbar disc
prolapse usually attempt to categorize prolapse type, but this is fre-
quently only a simple intra-operative assessment of site. Seldom is
size data from MR imaging provided. Neither a full classification
from NASS & Am Soc of Spine Radiol. (1) or an axial classification
(2) have been universally adopted by spinal surgeons. The aim of this
study was to define whether a combined MR classification had ade-
quate inter-observer reliability for comparative analyses.
Study design: We searched PubMed, Cinahl and Google using relevant
MESH headings for all classifications of disc prolapse in common clinical
usage. Taking this data we then constructed a composite scoring system
factoring site (central, lateral, foraminal, extra-foraminal) and size.
Outcome measures: MR scans of 120 consecutive patients with a
disc prolapse were analysed and scored independently by three sur-
geons. An online calculator was used to determine Randolph’s free-
marginal multi-rater Kappa (chance adjusted measure of agreement).
Results: 60 articles were analysed providing 3 classification systems
that were modified to 5 domains: level, site relative to the pedicle in
the axial plane, lateral extension, canal compromise and vertical
extent. This produced site (54 % L5/S1, 43 % L4/5, 3 % other) and
numerical size descriptors of which the commonest was: L.2.1.2
(central and lateral herniation (2), with prolapse at disc level
extending 1/3 across canal (1), and small vertical extension (2). The
three surgeons however, only agreed on the position of maximal
prolapse in 24 % of cases (Kappa = 0.27) and in calculated total size
score in 13 % (Kappa = 0.15). Two surgeons agreed in 92 % and
54 % respectively. There was a 25 % agreement for lateral extent,
60 % for degree of canal compromise and 58 % for vertical extent.
Conclusion: From the available literature data we produced a simple
coding system. However, the results were not sufficiently reproduc-
ible to be of value in comparative scientific data analyses. A better
3-D reconstruction method of size assessment is required.
1 Fardon D, Millette PC. Spine 2001;26(5):E93-113.
2 Mysliwiec LW, Cholewicki J, Wingelpleck MD, Eis GP. Eur Spine
J 2010;19:1087-93.
P7
MINIMALLY INVASIVE SPINE SURGERY IT’S
RATIONALE, BENEFITS AND EFFECTS
ON PATIENT OUTCOMES A COMPARISON
OF THE CLASSIC OPEN APPROACH
VERSUS MUSCLE SPARRING MINIMALLY
DISRUPTIVE APPROACH FOR MIS SURGERY
Donald Kucharzyk, Dushan Budimir
Orthopaedics, Crown Point, USA
Minimally Invasive Surgery for instrumented lumbar fusion is an
attractive concept with obvious advantages for the surgeon and patient
but the questions arises does it effect the outcomes of the patient. The
impetus for this technique centers on the wish to avoid paraspinal muscle
damage as seen with the classic open approach. One also questions the
approach in MIS as to whether a muscle splitting percutaneous approach
as seen with most MIS systems is more beneficial than a muscle sparring
minimally disruptive approach as offered with the MiniMax MIS system
and does this affect the patients’ outcomes as well?
A Study was undertaken to compare MIS surgery thru a muscle
splitting percutaneous approach and also a muscle sparring approach
versus the standard open approach spine fusion surgery.
Results revealed: In the Open Group: OR time(110 min), blood
loss(300 ml), duration of hospitalization(3.3 days), duration of nar-
cotic use(51 h), and fusion rate(92.8 %).
In the MIS I group: OR time (125 min), blood loss (100 ml), duration
of hospitalization (2.0 days), duration of narcotic use (25 h), and
fusion rate (93.3 %). In the MIS II groups: OR time (90 min,), blood
loss (75 ml) duration of hospitalization (1.5 days), duration of nar-
cotic use (12 h), and fusion rate (94.5 %).
Outcomes measurements revealed the following:
ODI: open 52.5 preop, 28.4 postop MIS I 53.9 preop, 19.2 postop MIS
II 54.1 preop 12.2 postop
BPS: open 16.4 preop, 8.1 postop MIS I 15.9 preop 5.1 postop MIS II
17.1 preop 2.0 postop
LPS: open 14.0 preop 6.7 postop MIS I 15.8 preop 3.7 postop MIS II
16.2 preop 1.0 postop
SF-36: open 27.6 preop, 39.7 postop MIS I 21.7 preop, 48.6 postop
MIS II 27.1 preop 49.6 postop.
These outcome measurement point to the positive effect of an MIS
approach to spine fusion but even better outcome measurements were
seen with the muscle sparring minimally disruptive approach via
MiniMax MIS System.
Conclusions: MIS has shown improvements in all outcome mea-
surements evaluated when compared to the classic open approach.
When further separated by MIS muscle splitting percutaneous
approach versus MIS muscle sparring approach minimally disruptive
approach, the muscle sparing approach performed even better and
when compared to the classic open approach it was more dramatic
and the outcome measurements were even more significant. Finally,
the most important conclusion for the surgeon was that similar fusion
rates were seen in all three studied groups.
P8
THE EFFECT OF LOCAL STEROID APPLICATION
COMBINED WITH PREEMPTIVE SURGICAL SITE
INFILTRATION IN REDUCING IMMEDIATE
POSTOPERATIVE PAIN AND OPIOID
CONSUMPTION FOLLOWING LUMBAR
MICRODISCECTOMY. A PROSPECTIVE
RANDOMISED CONTROLLED TRIAL
Efthimios Samoladas, Stavros Stavridis
2nd Orthopaedic Dpt, Aristotle University of Thessaloniki,
Thessaloniki, Greece
Aim of the study: To investigate whether preemptive surgical site
infiltration with local anaesthetic combined with before closing local
steroid application would be more effective compared to infiltration
alone in reducing immediate postoperative back pain and opioid
consumption, following lumbar microdiscectomy.
S722 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Patients and Methods: 60 patients undergoing one or two-level
discectomy were randomized to either Group A (infiltration + steroid,
30 patients) or Group B (infiltration only, 30 patients). After defining
the correct level under fluoroscopic guidance, all patients received a
preemptive infiltration of the surgical site with 10 ml of a 2 % lido-
caine and 1/10000 adrenaline solution. In Group A patients, a solution
consisting of 9 ml 2 % ropivacaine and 1 ml 3 mg/ml betamethasone
acetate was applied just before wound closure both intraforaminally
and retrograde epidurally with use of a small catheter. A standard
postoperative analgesic regime including the administration of 1 gr
paracetamol 9 3 i.v. was applied to all patients. 100 mg Tramadol
i.v. were administered at 3 h postop to those patients who required
further analgesia. Postoperative back pain was evaluated with use of
the VAS score at 1, 2, 3, 4, 6, 8, 12 and 24 h post-surgery. Patients’
opioid consumption was also recorded. Statistical analysis was per-
formed with use of the t Test for discrete variables and Fisher’s exact
test for categorical variables.
Results: There were no complications regarding neither the pre-
emptive infiltration, nor the steroid application. Overall none of the
Group A patients required further analgesia; while 12 Group B
patients received upon request 100 mg Tramadol i.v. 3 h postop
(P = 0.01). At 2 and 3 h postop the VAS score was significantly
lower in Group A (mean VAS = 1.6 at 2 h, 1.8 at 3 h) compared to
Group B (mean VAS = 2.3 at 2 h, 2.7 at 3 h) (P \ 0.05). Following
the Tramadol application, mean VAS score decreased in Group B up
4 h postop, while it remained low in Group A without any significant
difference among the two groups for the remaining time points tested.
Conclusions: Our results indicate that local corticosteroid application
combined with preemptive surgical site infiltration with local anaes-
thetic is more effective than infiltration alone in reducing immediate
postoperative back pain and opioid consumption, following lumbar
microdiscectomy. Both are also safe and easy to perform procedures
with no related complications.
P9
PREDICTORS FOR DURAL LESIONS REQUIRING
SURGICAL MEASURES IN THE TREATMENT
OF LUMBAL SPINAL STENOSIS: COMPARISON
OF A SINGLE CENTER WITH THE ‘‘RELIABLE’’
AND ALL OTHER SPINE TANGO CLINICS
Everard Munting, Christoph Roder, Rolf Sobottke, Emin Aghayev
Institute for Evaluative Research in Medicine, Bern, Switzerland
Background: Lumbar spinal stenosis is one of the most frequently
treated spinal diseases and a dural lesion is its most frequent com-
plication. We aimed at finding predictors for dural lesions requiring a
surgical intervention by analysing the Spine Tango registry data (form
versions 2005/06).
Methods: Inclusion criterion was a lumbar spinal stenosis with pos-
terior decompression (deco) surgery. A total of 9545 patients was
identified: n = 645 from the first author‘s center, n = 1962 from five
international ‘‘reliable’’ clinics with known and credible recording of
all surgical complications, and n = 6938 from all other Spine Tango
participants. The target variable was a dural lesion that required a
surgical measure.
Multivariate logistic regression was applied to adjust for differences
in patient age and gender, previous surgery (yes/no), extension of
lesion (1/2-3/4-5/C 5 segments) and type of surgical treatment (deco
only/deco with instrumented fusion).
Results: The raw dural lesion rate was higher in the single center
(11.2 %), followed by the reliable (6.6 %) and all other clinics
(3.0 %). The multivariate regression analysis revealed several pre-
dictors for the outcome. Deco alone had an odds ratio (OR) 1.65
(CI95 % 1.1-2.4) for dural lesion compared with deco and instru-
mented fusion. Patients with previous surgery had an OR 1.67 (1.2-
2.3) for a dural lesion compared with those without. Larger extensions
of lesion had an OR 1.65 (1.2-2.4), 1.84 (1.1-3.2), and 4.06 (1.8-9.1)
for 2-3, 4-5, [ 5 segments compared with 1-2 segments. Patients
from the single center and the reliable clinics had similar (single
center OR 1.59, 1.0-2.5; reliable clinics OR 1.63, 1.1-2.3) and higher
odds for dural lesions than patients in other clinics.
Discussion: Documentation of surgical complications in the Spine
Tango registry relies on individual surgeons‘ and clinics‘ honesty.
A Spine Tango code of conduct will be introduced in 2013 to foster
honest, transparent and monitored documentation. The difference in
proportions of relevant dural tears between the single center and
reliable clinics was not significant and even reversed after case mix
adjustment, which shows the importance of adjusted analyses. Dural
lesion rates of the reliable Spine Tango centers can probably serve as
authentic benchmark. Deco alone, previous spinal surgery and larger
extension of lesion were revealed as significant predictors for relevant
dural lesions in spinal canal stenosis surgery in the Spine Tango
dataset.
P10
DOES THE NEW SRS-SCHWAB CLASSIFICATION
SUFFICE TO DEFINE ADULT SPINAL DEFORMITY?
Ferran Pellise, Montse Domingo-Sabat, Emre Acaroglu,
Francisco J S Perez-Grueso, Ahmet Alanay, Ana Garcıa de Frutos,
Alba Vila-Casademunt, Joan Bago, ESSG European Spine Study Group
Spine Unit Vall Hebron Hospital, Barcelona, Spain
Background: The new Scoliosis Research Society Adult Spinal
Deformity (ASD) classification, published in May 2012 and based on
radiological criteria, has been shown to be reliable. The incidence and
patient’s characteristics for each curve type are still unknown. We
hypothesized that this classification may not identify homogeneous
groups of patients.
Patients and Methods: Radiological and health related quality of life
(HRQL) baseline data of patients with degenerative (DG) or idio-
pathic (ID) deformity, consecutively enrolled in a prospective
European multicenter database, was analyzed. Inclusion criteria:
age [ 18 ys and scoliosis [ 208, SVA [ 5 cm, pelvic tilt [ 258 or
thoracic kyphosis [ 608. Patients’ characteristics and incidence were
evaluated for each coronal curve type
Results: 368 patients, mean age 44.1 years (18 to 88), 83.9 % female,
were evaluated. Incidence of curve types: T 14.3 %, L 16.3 %, D
40.4 % and N 28.9 %. In N curve pattern 56.6 % of cases had minor
(20-308) coronal and 43.4 % pure sagittal deformity without coronal
deformity. ASD was idiopathic in 73.1 % of cases and degenerative in
26.9 %. Diagnostic groups had different mean ages (p \ 0.0001) (ID
36.2 y/DG 65.4 y). Idiopathic and degenerative curves had different
(p \ 0.0001) curve pattern distribution: T curve: 92 % ID vs 8 % DG;
L curve: 42.1 % ID vs 57.8 % DG; D curve: 95.6 % ID vs 4.3 % DG;
N curve: 54.4 % ID vs 45.5 % DG. Sagittal modifiers’ scores differed
(p \ 0.0001) among diagnostic groups too: Score 0: 86-88 % ID vs
11-13 % DG; Score +: 38-53 % ID vs 47-61 % DG; Score ++:
22-34 % ID vs 65-77 % DG.
We found clinically and statistically significant differences in SF36
PCS (p \ 0.01), ODI (p \ 0.001) and SRS-subtotal (p \ 0.01)
between T or D and L curves, L curves having worse HRQL scores.
These differences were found to disappear when idiopathic and
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S723
123
degenerative curves were analyzed separately. DG L and N patients
had worse HRQL scores compared to L and N ID patients: SF36 PCS
L curve 41.2 ID vs 33.4 DG (p \ 0.001); SF36 PCS N curve 45.4 ID
vs 34.2 DG (p \ 0.0001); ODI L curve 25.2 ID vs 49.5 DG
(p \ 0.0001); ODI N curve 18.3 ID vs 51.8 DG (p \ 0.0001); SRS22
subtotal L curve 3.3 ID vs 2.6 DG (p = 0.0002); SRS22 subtotal N
curve 3.6 ID vs 2.9 DG (p \ 0.0001).
Conclusion: In the new SRS-Schwab ASD classification D and N
patterns are predominant. This classification does not identify
homogeneous groups of patients. Adding the etiology parameter to
that of coronal curve pattern increases homogeneity of patient
subgroups.
P11
DO ‘‘DOERS’’ AND ‘‘REFERRERS’’ DIFFER
IN THEIR RATINGS OF THE APPROPRIATENESS
OF SURGERY FOR LUMBAR DEGENERATIVE
SPONDYLOLISTHESIS?
Francois Porchet, Felix Steiger, Valerie Pittet, Hans-Jurgen Becker,
John-Paul Vader, Anne F Mannion, and the Zurich Appropriateness
of Spine Surgery (ZASS) group
Spine Center, Schulthess Klinik, Zurich, Switzerland
Introduction: The RAND Appropriateness Method (RAM) is one of
the most respected methods for defining appropriate medical care.
Given the paucity of evidence from RCTs in spine surgery, the RAM
may represent a reliable, unbiased and clinically relevant approach to
assessing the appropriateness of treatment in various spinal patholo-
gies. It combines a detailed literature review with a modified Delphi
panel approach to gauge collective expert opinion. The panel should
be multidisciplinary, to reflect the variety of specialties involved in
treatment decisions. This study evaluated the difference in ‘‘appro-
priateness of surgery’’ (AoS) ratings between surgeons (‘‘doers’’) and
non-surgeons (‘‘referrers’’) participating in a RAM expert panel to
develop criteria for the surgical management of lumbar degenerative
spondylolisthesis (LDS).
Methods: The risks/benefits of treatment were summarised in a sys-
tematic review. Clinical scenarios comprising combinations of signs,
symptoms and other clinical parameters in LDS were then generated.
The AoS for each scenario was rated on a 9-point scale (1, inappropriate
to 9, appropriate) by an international, multidisciplinary group of 12
experts (8 surgeons, 4 non-surgeons (physiatrists/rheumatologist/
internist)). The ratings were analysed with respect to the appropriateness
of any type of surgery (decompression ± fusion ± instrumentation).
Results: 744 hypothetical scenarios were generated. Overall, sur-
geons gave significantly (p \ 0.0001) higher ratings than non-
surgeons (+0.68 points difference), especially for the scenarios in the
category ‘‘back pain only’’ (+0.97 points). The least discrepancy was
found for the scenarios in the category ‘‘radicular pain with no LBP
and no instability’’ (+0.12 points). Multiple regression revealed that
significant (p \ 0.0001) factors influencing the surgeon vs non-sur-
geon difference in ratings were the presence of yellow flags
(difference narrowed) and severe disability (difference increased).
Discussion: The study quantified the more conservative stance of
non-surgeons in relation to the appropriateness of surgery for LDS.
The findings may reflect the different case mixes typically seen by
surgeons and non-surgeons and their respective appreciation of the
risks and benefits of surgery compared with alternative treatments.
The results emphasise the importance of having a mix of ‘‘doers’’ and
‘‘referrers’’ when developing treatment appropriateness criteria.
P12
SPONTANEOUS REDUCTION TECHNIQUE
OF MODERATE TO HIGH GRADE
SPONDYLOLISTHESIS VIA MINIMALLY
INVASIVE, MINI-OPEN POSTERIOR LUMBAR
INTERBODY FUSION
Hyeun Sung Kim, Ki Hyun Jeon, Chang Il Ju
Neurosurgery, Daejeon, Korea (ROK/South Korea)
Purpose: The purpose of this study was to achieve the safe and
easy technique for minimizing the neurologic deterioration and
maximizing the reduction of spondylolisthesis using mini-open,
posterior-lumbar interbody fusion under circumferential releasing
technique.
Material & Methods: This study involved 54 cases who received mini-
open PLIF with percutaneous screwing, due to more than Mayerding
Grade II spondylolisthesis. Mean age was 60.19 year, mean follow-up
period was 32.67 months. According to the rate of slippage, 37 cases
included in Grade II (25 % * 49 %), 14 cases included in Grade III
(50 %-74 %) and 3 cases included in Grade IV (75 % *). The mean rate
of slippagewas 45.85 %. All patient received mini-open, posterior-lumbar
interbody fusion under epidural anaesthesia using the rimmed head screw
type percutaneous screw system. A circumferential releasing technique
was performed according to the following sequence: 1. Intraoperative
postural reduction position; 2. facet joint mobilization decompression; 3.
Segmental Mobilization; 4. Increasing sacral slope; and 5. Increasing the
anterior disc height. The clinical results were evaluated by visual analogue
scale (VAS) and Oswestry Disability Index, and Radiological results were
evaluatedby degreeof slippage reduction, degreeof disc height restoration
and postoperative neurological complications.
Results: The degree of slippage rate preoperative was: 45.85 % to
postoperative: 9.35 %. The degree of disc space was preoperative:
5.37 mm to postoperative: 12.15 mm. Back/Leg Visual Analogue
Scale and Oswestry Disability Index decreased from 6.28/7.83 to
1.85/1.41, 68.37 to 16.46, respectively.
There was no definite motor weakness after operation. However, 2
cases (3.70 %) suffered only transient, mild, motor weakness and 4
cases (7.41 %) suffered transient sensory change. There were no signs
of instrumentation failure or fusion failure.
Conclusion: According to the results, we could obtain maximal
reduction of spondylolisthesis under minimal neurologic deterioration
in the cases of a moderate to high grade of spondylolisthesis using the
circumferential segmental releasing technique.
P13
PATTERNS OF LUMBAR PAIN: AN EFFECTIVE
APPROACH TO LUMBAR AND SCIATIC PAIN
IN PRIMARY CARE IN OCCUPATIONAL
MEDICINE. COMPARATIVE STUDY OF TWO
RETROSPECTIVE COHORTS OF 3627 PATIENTS
Jaime Diaz de Atauri Bosch, Oscar Zabalza Mantilla, Mikel Ayala Garcia
Clinica Ercilla - Mutualia Vizcaya. Spine Unit, Bilbao, Spain
Patterns of lumbar pain: An effective approach to lumbar and sci-
atic pain in primary care in occupational medicine. Comparative
study of two retrospective cohorts of 3627 patients.
S724 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Objective: We present a new approach to lumbar and sciatic pain in
primary care by grouping patients according to different pain patterns
noted during history-taking and physical examination. The aim is to
assess whether differences exist between managing lumbar and sciatic
pain in the working population when grouping patients according to
pain patterns and the possible health repercussions of not doing so.
Materials and methods: We performed a retrospective study of two
cohorts of patients treated for lumbar and sciatic pain at the accident
insurance company, Mutualia, in the provinces of Alava and Vizcaya
(Spain) in 2012. In Alava (G1), patients were managed according to
pain patterns, while in Vizcaya (G2), they received conventional
treatment. Diagnosis, number of sick days and mean duration, number
of additional tests, hospital admissions, surgical interventions and
referrals to rehabilitation (and duration) were studied. Statistical
analysis was performed using SPSS software (Chi squared and Stu-
dent t) with a sensitivity of 95 %.
Results We reviewed 3627 cases: 593 for G1 and 3032 for G2. The
sick leave rate was 38.78 % (G1) and 44.95 % (G2); the statistical
difference was significant (P \ 0.01). Average sick leave was 14.36
(G1) and 19.98 (G2) days (P \ 0.01). Rehabilitation sessions totalled
14.95 (G1) and 21.28 (G2) (P \ 0.01). We found no significant dif-
ferences in the number of additional tests per patient (0.16 vs 0.17),
percentage of hospital admissions (2.36 % vs 3.49 %), inpatient bed
days (3.92 vs 1.72) or in the percentage of surgical interventions
(2.02 % vs 2.20 %).
Conclusions: A marked difference in pain management was observed
after patients were grouped according to pain patterns. In primary
care, this is an effective way to indicate the duration of sick leave and
rehabilitation therapy. These results have already modified treatment
in G2, given the resulting financial and health care repercussions for
Mutualia.
P14
POSTERIOR TRANS-PEDICULAR FIBULAR
GRAFTS AND INTERFERENTIAL SCREWS
TO TREAT L5-S1 SPONDYLOPTOSIS. REPORT
ON FOUR CASES WITH 9.5 YEAR FOLLOW-UP
Javier Pizones, Alberto Nunez, Felisa Sanchez-Mariscal,
Patricia Alvarez-Gonzalez, Lorenzo Zuniga, Enrique Izquierdo
Spine Unit. Orthopaedic surgery. Hospital Universitario de Getafe,
Madrid, Spain
Introduction: Several techniques have been described to treat high-
grade spondylolisthesis. Reported historical complications are neuro-
logic injuries, pseudarthrosis, progression of slip, and instrumentation
failure. We present a posterior-only approach with partial reduction
and instrumentation to treat spondyloptosis. Interbody fusion is pro-
vided by trans-pedicular fibular struts inserted through S1 capturing
L5, avoiding central neural manipulation. Graft stress is protected
using interferential screws placed through these same pedicles.
Methods: Retrospective revision of four cases with grade V spond-
ylolisthesis. We analyzed preoperative, postoperative and final
follow-up clinical and radiographic data, with final SRS-22 outcomes.
Pelvic Incidence (PI), Sacral Slope (SS), Pelvic Tilt (PT), L5 Inci-
dence (L5I), Lumbar Lordosis (LL), L5 Slip Angle (L5SA),
Lumbosacral Kyphosis (LSK), and Sagittal Vertical Axis (SVA) were
measured. Fusion and complications were recorded.
Results: The mean age was 25.7 ± 5.7 yr. All were men with istmic
spondyloptosis (Meyerding grade V; type 5/6 SDSG classification).
One revision and three primary surgeries. The median fused levels
were 3 (3, 3.75), the mean operative time was 6.1 ± 0.8 h, the
median transfusion units were 2 (2, 5). The median follow-up was
114 months (45, 147.7). The lumbar/radicular pain assessed by VAS
reduced from preoperative 7.1 ± 2.4 to postoperative 1.3 ± 1.3. PT
improved 9.78, L5I improved 158, LSK and L5SA improved over 308and maintained over time. SVA improved 1.6 cm but lost them at
final follow-up. The SRS global satisfaction was 4.6 ± 0.2. We have
not seen any neurological complications, graft fractures, pseudar-
throsis, progression of slip, or instrumentation failure.
Conclusion: This technique yielded satisfactory clinical results in the
treatment of L5-S1 spondyloptosis. It provided stable anterior support
and high fusion rate by means of the transpedicular fibular grafts
while interferential screws protected from graft failure. It avoided
anterior approach related complications and mid-body inserted grafts
neurologic risks.
P15
IS PELVIC INCIDENCE AS CONSTANT
AS EVERYONE KNOWS?: CHANGE OF PELVIC
INCIDENCE IN SURGICALLY BALANCED ADULT
SAGITTAL DEFORMITY
Jung-Hee Lee, Jin-Soo Kim, Il-Heon Choi, Hyun-Seok Oh,
Chul-Hee Lee, Dae-Hyun Tak
Orthopaedic Surgery, Seoul, Korea (ROK/South Korea)
Objectives: To analyze the disparity of pelvic incidence (PI) before
and after surgery and to evaluate the its effect on final sagittal balance
in the surgically fixed lordosis with immediate postoperative optimal
sagittal balance following correction of adult sagittal deformity.
Summary of Background Data: Previous investigations have been
recognized pelvic parameters as a critical role in the setting of fixed
sagittal deformity. PI is as constant as everyone knows. PI might be
changed reciprocally because increased shear force following over-
corrected fixed lumbar lordosis on mobile sacroiliac joint. The
disparity of PI after surgery according to surgical methods and its
effect on final follow-up have not been reported.
Methods: A prospective study of 29 subjects with adult spinal
deformity (average age 67.9 years) who resulted optimal sagittal
balance at final follow-up following consecutive sagittal correction
with a minimum 2-year follow-up was carried out. The surgical change
of spinopelvic parameters were analyzed including PI, sacral slope,
pelvic tilt, lumbar lordosis, thoracic kyphosis and sagittal balance.
Results: The mean lumbar lordosis was 0.2 ± 19.3� before surgery, -
59.3 ± 10.9� after surgery with PSO (n = 20), ALIF (n = 20, 33
segments) and PLIF (n = 19, 36 segments) and -57.5 ± 11.4� at final
follow-up. The sagittal vertical axis was +14.8 Cm before surgery, -
0.7 Cm after surgery and 2.2 Cm at final follow-up. The mean PI was
increased in 49.4� before surgery, 55.2� after surgery, 57.5� at post-
operative 1-years and 58.8� at final follow-up (p = 0.02). The mean
disparity of PI preoperative and final follow-up was 11.4� without
sacropelvic fixation (n = 18) and 6.0� with sacropelvic fixation
(n = 11) (p = 0.002). Analysis revealed the disparity of PI to be
significantly higher in non-sacropelvic fixation and correlated with
follow-up period (r = 0.442, p = 0.016) but no to age, BMD, number
of fused segments, correction methods, corrected lumbar lordosis or
sagittal balance.
Conclusions: PI was increased in all patients with optimal sagittal
balanced adult sagittal deformity following overcorrection of lumbar
lordosis. The disparity of PI after surgery was significantly higher in
non-sacropelvic fixation and was shown to possess significant
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S725
123
correlation to follow-up period, but there are no influence on sagittal
balance at final follow-up.
P16
ANALYSIS OF THE OPTIMAL SCREW DENSITY
FOR CORRECTION OF ADOLESCENT
IDIOPATHIC SCOLIOSIS
Kensuke Shinohara, Yoshihisa Sugimoto, Tomoyuki Takigawa,
Shinya Arataki, Masato Tanaka, Toshifumi Ozaki
Orthopaedics, Okayama city, Japan
Introduction: We have performed surgical correction of adolescent
idiopathic scoliosis (AIS) using thoracic pedicle screw (TPS). We
usually insert pedicle screw as many screws as possible in order to
archive good correction. However, optimal screw density for correction
of AIS is unknown. The purpose of this study is to analyze optimal screw
density for correction of AIS based on flexibility of spinal curve.
Materials and methods: Forty patients with AIS were retrospectively
reviewed for this study. Inclusion criteria: (1) Patients who were
treated by TPS at our department; and (2) a minimum follow-up of
one year. There were five males and 35 females, with and average age
of 16 years (range, 13 to 23 years) at the time of operation. We
measured the pre- and postoperative Cobb angle in the upright
position, preoperative traction Cobb angle, screw density and rigidity
of curve (RC). The measurements were performed between the upper
and lower end vertebra, and defined as follows:
Screw density: number of inserted screw/(number of vertebra body 2)
100 (%)
Rigidity of curve (RC): traction Cobb angle/preoperative standing
Cobb angle 100 (%)
We calculated Spearman’s correlations between the screw density and
RC, and correction rate.
Results: Average pre- and postoperative standing Cobb angle were 58
degrees (range 38 to 89) and 15 degrees (range 0 to 40), respectively.
The mean correction rate was 75 percent. The average screw density
and RC were 80 percent (range, 14 to 100) and 63 percent (range, 36
to 91), respectively. Calculation of Spearman’s correlations between
the screw density and RC, and correction rate gave coefficients 0.23
and 0.48, respectively. Regardless of number of screws, average
correction rate of patients with non-rigid curve (RC was 50 percent or
less) was 85 percent.
Conclusions: Our study demonstrates that RC correlated well and
more closely with the correction rate, than did the screw density.
Increasing number of pedicle screw did not always mean good cor-
rection. Patients who had non-rigid curve (RC: 50 percent or less) can
be treated with fewer pedicle screws.
P17
LUMBAR DECOMPRESSION FOR CENTRAL
CANAL STENOSIS IN THE ELDERLY
Matthew George Stovell, Tim Pigott, Chris Barrett
Neurosurgery, Liverpool, UK
Objective: Lumbar canal stenosis due to a combination of anterior
compression from disc bulges and posterior compression from
hypertrophy of the ligamentum flavum and facet joints can cause
pain, sensory disturbance, reduced mobility and autonomic dysfunc-
tion. These processes deteriorate with increasing age, which will have
an increasing impact on the aging population of Europe. With the
improvement of surgical techniques and the safety of anaesthesia,
surgery is being performed on a larger proportion of increasingly
elderly patients. We compared the post-operative outcome and
complication rate of primary lumbar laminectomy in very elderly
patients, to their younger cohort.
Methods: Data were collected prospectively using the Spine Tango
database. All patients who underwent primary lumbar decompression
during 2012 for central stenosis were included. Patients undergoing
instrumentation were excluded. Only patients with both pre-operative
and post-operative COMI scores were included. Patients were split
into two groups (C 75 years old & \ 75 years old).
Results: Complete data were available for 43 patients \ 75 years old
and 16 patients C 75 years old. In the younger group, pre-operative
COMI score was 8.0 ± 1.6 (mean, S.D.) and post-operative
improvement was 3.4 ± 2.6 (mean, S.D.). In the more elderly group,
pre-operative COMI score was 8.1 ± 1.5 (mean, S.D.) with a post-
operative improvement of 4.0 ± 2.1 (mean, S.D.). There were 7
unintentional durotomies in the younger group (16 %) and 1 in the
elderly group (6 %). There were no other intra-operative complica-
tions in either group. Intra-operative mortality was zero.
Conclusions: The reduction in COMI score in the more elderly group
was greater than that in the younger group (although not statistically
significant). The rate of complication (durotomies) was also lower.
We believe that when patients are appropriately selected, lumbar
laminectomy for lumbar canal stenosis is an effective surgical inter-
vention in extreme age.
P18
POSTERIOR VERTEBRAL COLUMN RESECTION
FOR ADULT SPINAL DISORDERS: EFFICACY,
COMPLICATIONS AND RISK FACTORS
Meric Enercan, Gurkan Gumussuyu, Sinan Kahraman,
Cagatay Ozturk, Tunay Sanli, Bekir Yavuz Ucar, Ramazan Soydan,
Burak Abay, Azmi Hamzaoglu, Ahmet Alanay
Istanbul Spine Center, Istanbul, Turkey
ABSTRACT BODY:
Summary: (80 words max): PVCR provides satisfactory radiographic
outcome for the treatment of complex spinal disorders.
Introduction: Aim is to analyze the results, complications and related
risk factors of PVCR performed on a consecutive series of adult pts
with spinal disorders.
Methods: 56 adult patients (27 f, 29 m) managed by PVCR having
more than 2 years follow-up were included. Indications were scoliosis
(9), acute fracture (15), posttraumatic kyphosis (8), kyphosis (9), PJK
(7), spondylodiscitis (6), ankylosing spondylitis (2). Preop, postop
and f/up X-Rays were evaluated to measure deformity, to reveal
mechanical complications. Hospital charts were evaluated for medical
complications. Risk factors and their correlation with complications
were analyzed.
Results: v age was 45 (19 - 85) years at the time of the operation.
Mean f/up was 4.6 (2-10) years. PVCR was performed at T level (23),
TL level (29) and L level (4). Av. operation time was 441 (240-900)
minutes and blood loss was 2452 (1000-6100) ml. Av instrumentation
levels were 9 (4-18). Preop mean coronal plane curve was corrected
from 87.6 degree (46-120) to 47.3 degree (5-77) (46 %). Preoperative
thoracic kyphosis was corrected from 65.1 degree (24-110) to 47.6
S726 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
degree (29-84) (27 %). There was no significant loss of correction at
final f/up (p [ 0.05). Overall complication rate was 55.4 %, including
29 patients had 35 minor complications (51.8 %) and 4 patients had 4
major complications (7.1 %). Major complications were pneumonia
(2), pulmonary embolism (1) and superior mesenteric artery syn-
drome (1). There was no neurological complication. Patient age,
PVCR level, etiology and revision surgery were not associated with
major complications (p [ 0.05). Etiology (acute trauma) was asso-
ciated with major complications (p = 0.045). Total and minor
complications were found higher in males (p = 0.014, p = 0.025,
respectively). Fusion was observed in all patients.
Conclusion: PVCR provides satisfactory radiographic outcome for
the treatment of complex spinal disorders. However, it is a technically
demanding procedure with high complication rates (major: 7.1 %,
minor: 51.8 %) and should be selected only when other alternatives
are not appropriate.
P19
AUGMENTATION OF PEDICLE SCREWS
WITH CEMENT HELPS TO PREVENT
MECHANICAL FAILURE IN ELDERLY PATIENTS
WITH [ 5 LEVELS INSTRUMENTATION: A CT
ANALYSIS OF 688 PEDICLE SCREWS
Meric Enercan, Sinan Kahraman, Cagatay Ozturk, Gurkan
Gumussuyu, Tunay Sanli, Bekir Yavuz Ucar, Levent Ulusoy,
Azmi Hamzaoglu, Ahmet Alanay
Istanbul Spine Center, Istanbul, Turkey
Introduction: Cement augmentation of pedicle screws (PS) is one of
the several measures to prevent screw failure in elderly patients with
osteoporosis. The aim of this study is to analyse the efficacy and
complications of cement augmentation in elderly patients with long
([ 5 levels) instrumentation.
Methods: A retrospective analysis of 55 patients who had cement
augmented PS was performed. All patients had CT scans taken
minimum 2 years after index operation. CT’s were analysed to
determine PS loosening, cement leakage and fusion rates at aug-
mented levels. Standard vertebroplasty technique was used for
augmentation. Prior to cement injection, mechanical aspiration of the
vertebral bodies was done through working cannula to prevent cement
emboli. Cement injected was 4 cc/lumbar and 2 cc/thoracic vertebrae.
Screws were placed immediately after cement injection.
Results: There were 688 cement augmented PS with a mean f/up of
45 (24-116) months. Average age (40 F, 15 M) was 69 (50-85) years.
Diagnosis were spinal stenosis in 41, trauma in 1, infection in 5 and
revision surgey in 8 patients. Av. number cement-augmented screw/
patient was 13 (4-32). Interbody fusion was done in 37 patients (100
levels). There were 10 (1.4 %) loose screws in 7 (%12.7) patients.
None had pulled out. Screw loosening was at fused levels in all except
one with pseudoarthrosis. All loosed screws were at the levels without
interbody fusion. One patient with pseudoarthrosis had rod breakage
and underwent a revision operation. There was no vertebral body
fracture at the augmented levels. Extravasation of cement was seen in
7 (%12.7) patients, none in spinal canal. 3 (%5.4) patients had
asymptomatic pulmonary cement emboli. 3 (%5.4) patients had deep
wound infection, they were treated successfully with debridement and
antibiotic therapy with no need to instrument removal.
Conclusion: Cement augmentation of PS in elderly osteoporotic
patients prevents screw pull-out. Screw loosening can be seen with a
very low rate and at the levels without interbody fusion.
P20
COHORT STUDY OF RISK FACTORS RELATED
TO REOPERATION AFTER MICROSURGICAL
BILATERAL DECOMPRESSION VIA A UNILATERAL
APPROACH (MBDU) FOR TREATMENT
OF DEGENERATIVE LUMBAR DISEASE
Minori Kato, Hiroaki Nakamura, Koji Tamai, Kazunori Hayashi,
Akira Matsumura, Sadahiko Konishi
Orthopaedic Surgery, Osaka, Japan
Purpose: Some authors have reported good clinical outcomes follow-
ing microsurgical bilateral decompression via a unilateral approach
(MBDU). This approach entails a less invasive technique that preserves
the posterior elements. Some studies have also reported the good results
of MBDU for LCS in cases with instability or scoliosis. However, few
reports examine the risk factors that might preclude certain patients
from MBDU. The purpose of this research was to evaluate the radio-
graphic risk factors of required reoperations after MBDU.
Methods: Between 2007 and 2010, 255 patients underwent MBDU our
institution. Of them, 48 were lost follow up. A total of 207 patients (309
discs; 88 women 119 men; age range, 40-86 years; mean age, 70 years)
were included in this study (follow-up ratio: 81.2 %), and the duration of
the follow-up was 24 months. The radiological indications were lumbar
spinal stenosis, degenerative lumbar spondylolisthesis with slip-
page\ Meyerding Grade I, or degenerative lumbar scoliosis with\ 20�Cobb’s angle. We investigated the prevalence of cases that required
reoperation, these cases’ clinical characteristics, and the risk factors
associated with reoperation after MBDU.
Results: Reoperation after MBDU was needed in 13 cases (6.3 %). The
cause of reoperation was radicular pain due to intraforaminal stenosis in 6
cases, development of disc herniation in 4 cases, exacerbation of disc
degeneration in 2 cases, and low back pain due to intraspinal facet cyst in
1 case. The duration from the initial operation to reoperations for radic-
ular pain due to intraforaminal stenosis or due to the development of disc
herniation was 6 months, which is very short for this condition. The
Japanese Orthopedic Association (JOA) Scores of the cases was 9.8
points preoperatively. It aggravated to 7.8 points before the second
operation, and reached 12.8 points at the final follow up. The L4/5 cases
with reoperation were significantly associated with scoliotic disc wedg-
ing and lateral listhesis in the prone position. The odds ratio of scoliotic
disc wedging and lateral listhesis was 9.88 and 12.6, respectively.
Conclusions: There is no consensus about the inclusion criteria of
MBDU for LCS in cases involving AP slippage, lateral listhesis, or
scoliotic disc wedging, such as spondylolisthesis and degenerative sco-
liosis. From this study, surgeons should be cautious about indicating
MBDU for cases with scoliotic disc wedging or lateral listhesis in L4/5.
P21
CLINICAL CHARACTERISTICS OF INTRASPINAL
FACET CYSTS FOLLOWING MICROSURGICAL
BILATERAL DECOMPRESSION VIA A UNILATERAL
APPROACH FOR TREATMENT OF DEGENERATIVE
LUMBAR DISEASE
Minori Kato, Hiroaki Nakamura, Koji Tamai, Kazunori Hayashi,
Akira Matsumura, Sadahiko Konishi
Orthopaedic Surgery, Osaka, Japan
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S727
123
Purpose: Primary intraspinal facet cysts in the lumbar spine are
uncommon, but it is unclear whether cyst incidence increases following
decompression surgery and if these cysts negatively impact clinical
outcome. We examined the prevalence, clinical characteristics, and the
risk factors associated with intraspinal facet cysts after microsurgical
bilateral decompression via a unilateral approach (MBDU) which
entails a less invasive technique that preserves the posterior elements,
including the paravertebral muscle, facet joints, and lamina.
Methods: We studied 230 patients treated using MBDU for lumbar
degenerative disease (133 men and 97 women; mean age, 70.3 years).
Clinical status, as assessed by the Japanese Orthopedic Association
(JOA) score and findings on X-ray and magnetic resonance images,
was evaluated prior to surgery and at both, 3 months and 1 year after
surgery. The prevalence of intraspinal facet cysts was determined and
preoperative risk factors defined by comparing presurgical findings
with clinical outcomes.
Results: Thirty-eight patients (16.5 %) developed intraspinal facet cysts
within 1 year postoperatively, and 24 exhibited cysts within 3 months.
In 10 patients, the cysts resolved spontaneously 1 year postoperatively.
In total, 28 patients (12.2 %) had facet cysts 1 year postoperatively. The
most common sites in all groups were L3–4 and L4–5; few cysts
developed at L2–3 and L5–S1. The mean JOA score of patients with
cysts 1 year postoperatively was significantly lower than that of patients
without cysts. This poor clinical outcome resulted from low back pain
that was not improved by conservative treatment. Most cases with
spontaneous cyst disappearance were symptom-free 1 year later. The
preoperative risk factors for postoperative intraspinal facet cyst forma-
tion were instability (OR: 2.47, P = 0.026), scoliotic disc wedging (OR:
2.23, P = 0.048), and sagittal imbalance (OR: 2.22, P = 0.045).
Conclusions: Postoperative intraspinal cysts should be recognized as
a common cause of postoperative symptom deterioration following
MBDU. Postoperative intraspinal facet cyst formation is a common
cause of poor clinical outcome in patients treated using MBDU. We
suggest caution in using MBDU for patients with instability, scoliotic
disc wedging, or sagittal imbalance, because a fusion operation
should be considered as an alternative in such situations.
P22
DEVELOPMENT OF A CLINICAL DECISION TOOL
TO SUPPORT SPINE SURGEONS IN THE TRIAGE
OF CHRONIC LOW BACK PAIN PATIENTS
Miranda van Hooff, Jan van Loon, Jacques van Limbeek,
Marinus de Kleuver
Sint Maartenskliniek Research, Nijmegen, Netherlands
Introduction: Chronic Low Back Pain (CLBP) is the most common
complaint for patients to visit a spine surgeon. International guide-
lines recommend developing a system that helps to direct both
surgical and non-surgical interventions. In Sint Maartenskliniek in the
Netherlands, a specialized hospital for spine care, a clinical decision
tool has been developed to support patient-triage. The tool is based on
evidence and professional consensus (Delphi procedure) and consists
of a web-based screenings questionnaire and a decision algorithm.
Patients presenting with CLBP are systematically followed over time.
We speculate that different patient profiles might be identified likely
to benefit from different recommended interventions such as surgery
or a Combined Physical and Psychological (CPP) program.
Purpose: To evaluate pre-intervention patient profiles based on
indicators predicting favorable outcome in spine surgery or the evi-
dence-based CPP program.
Methods: To attend a first consult, new patients have to complete an
extensive web-based screenings questionnaire (based on 48 predictive
indicators in 5 domains: sociodemographic, pain, somatic [red flags],
psychological [yellow flags], and functioning & quality of life). The spine
surgeons follow their decision making process as usual. Between April
2012 and March 2013 1,106 new CLBP patients completed the screen-
ings questionnaire: 82 (7.4 %) were indicated for spinal surgery and 97
(8.8 %) for the CPP program. A cross-sectional study on the screening
data was performed. Chi square tests for categorical variables and inde-
pendent Students’t tests for continuous variables were used to evaluate
differences in patient characteristics.
Results: Significant differences for: ‘age’, ‘leg pain intensity’, ‘pre-
vious back surgery’, ‘pension income’, ‘compensation sick leave’,
‘pain duration’(over 2 years), ‘yellow flags’, ‘expectations work
return’, and ‘expectations recovery’. Surgery patients e.g. reported
more leg pain, more previous surgeries, and shorter pain duration.
Although expected, surprisingly no significant differences between
cohorts were found for red flags and co-morbidities.
Discussion: Although some differences were found, large cohorts
with long follow-up periods are needed to be conclusive about the
probability of success in different treatment modalities. If indeed
these profiles can be identified, it would help practitioners to triage
the right patients to the spine surgery clinics. This would potentially
increase the effectiveness of these clinics, improve outcomes, and
lead to more appropriate use of limited health care resources. To our
knowledge this is a first attempt to find differences in profiles, based
on a wide range of indicators predicting treatment outcome. Since the
patient flow and assignment is still on-going, we will present the most
recent results at the time of the meeting.
P23
CLINICAL OUTCOMES OF A COMBINED
PHYSICAL AND PSYCHOLOGICAL PROGRAM
IN A LARGE COHORT OF LONGSTANDING
CHRONIC LOW BACK PAIN
Miranda van Hooff, John O’Dowd, M Spruit, Marinus de Kleuver,
Jeremy Fairbank, Jacques van Limbeek
Sint Maartenskliniek Research, Nijmegen, Netherlands
Introduction: Combined physical and psychological (CPP) programs
are widely recommended in international guidelines for Chronic Low
Back Pain (CLBP), but not often implemented. A two-week CPP
program is delivered in partnership with the spine surgeons of Sint
Maartenskliniek, the Netherlands. In a previous study the participants
(n = 107) learned to manage CLBP, improved in functional status
and quality of life at one-year follow up. After two years, the same
cohort showed maintenance of this improvement. As systematic
outcome measurement is part of the program, a large database
(n = 955) with one-year data is available.
Purpose: Review of the one-year follow-up clinical outcomes of a
large cohort (n = 848) and compared the results with previously
published results (n = 107).
Methods: Pre-treatment age (43.4 years [SD 8.4]), CLBP duration
(12.3 years [SD 10.9]), patients at work (70 %), and spinal surgery
before (32 %) were compared. Primary outcome: functional status
(Oswestry Disability Index [ODI; 0-100]). Secondary outcomes: self-
efficacy (Pain Self Efficacy Index [PSEQ; 0-60]), and Quality of Life
(SF36 Physical Component Scale [SF36PCS; 0-100])). Chi square
tests for categorical variables and independent Student’s t tests for
continuous variables were used to evaluate differences in pre-
S728 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
treatment characteristics. For the outcomes a Repeated Measures
analysis of variance was used to identify changes over time (within-
subject factor; R2) and to compare differences between cohorts
(between-subject factor). The one-year follow-up proportion of CLBP
patients reaching a functional status equivalent to an acceptable or
‘normal’ value (ODI B 20), is calculated.
Results: Except for age (48.0 [SD 11.6], t = -4.0, p \ 0.001), no
significant differences in pre-treatment characteristics were found.
The mean primary outcome score showed a similar pattern:
improvement immediately after following the program and mainte-
nance of results over time (ODI df(1,848), F = 917.0, p \ 0.001,
R2 = 0.52). Secondary outcomes showed the same pattern. Com-
pared to previously reported (n = 107), all outcomes showed
significantly more improvement over time. One-year follow-up pro-
portion reaching ODI ‘satisfactory’ value: 50.1 %.
Conclusion: The study results contribute to the evidence for the
efficacy of this CPP program. Patients improve during the pro-
gramme, have further improved at one year follow up, and half of the
patients improve such that their function is not significantly restricted
to a normal range.
P24
CAUDA EQUINA SYNDROME, TIMING
OF SURGERY AND AUTONOMIC OUTCOME
Nisaharan Srikandarajah, Simon Clark, Tim Pigott, Martin Wilby
Neurosurgery, Liverpool, UK
Objectives: Cauda equina syndrome (CES) is a severe neurological
disorder most commonly due to lumbar disc herniation with signifi-
cant compression on the cauda equina. The most distressing
consequence generally is loss of bladder control. There is much
debate regarding timing of surgery. Our aim was to analyse if oper-
ating within the 48 h actually made any difference to bladder
function.
Methods: We retrospectively reviewed 50 patients who had under-
gone surgery for CES due to herniated lumbar disc between 2000 and
2007 at a single neurosurgical centre. All cases were verified with
MRI lumbar spine. Data collected included age, pain distribution, date
of hospital admission and operation, level of operation, length of
autonomic symptoms before operation, time to initial follow up and
autonomic outcome. Presentation was categorized into cauda equina
syndrome with retention (CESR) and cauda equina syndrome
incomplete (CESI). Outcome measures of were documented at initial
follow up.
Results: 50 patients of whom 30 were female and 20 were male with
an average age of 42 years. All patients had emergency decompres-
sive surgery within 24 to 48 h of admission to the neurosurgical unit.
37 patients presented with unilateral leg pain and 13 with bilateral leg
pain. Average follow up time was 81 days. 32 patients presented with
CESI and 18 patients presented with CESR. For all the 15 CESI
patients operated within 48 h of onset of autonomic symptoms normal
bladder function was seen at follow up however with 15 CESI
patients operated after 48 h 2 had a negative outcome of bladder
dysfunction. For the 18 CESR patients operating within 24 h, within
48 h or after made no significant difference to the outcome.
Conclusions: In our study emergency decompressive surgery within
48 h of onset of autonomic symptoms in CESI patients can prevent
bladder dysfunction. This encourages prompt referral and surgical
management within 48 h of patients presenting with CESI to reduce
the possibility of bladder dysfunction. For CESR patients operating
within 48 h made no difference to their outcome.
P25
RELATIONSHIP BETWEEN SEDIMENTATION
SIGN AND MORPHOLOGICAL GRADE
IN SYMPTOMATIC LUMBAR SPINAL STENOSIS
Pietro Laudato, Gerit. Kulik, Katarzyna Pierzchala,
Constantin Schizas
Orthopedics, Centre Hospitalier Universitaire Vaudois and the
University of Lausanne, Lausanne, Switzerland
Introduction: Dural sac cross sectional area has been the main
radiological measurement used in clinical practice. The morphologi-
cal grading of stenosis (rootlet/cerebrospinal fluid) consists of 4
grades (A to D), better presents the degree of entrapment of the neural
structures and carries a prognostic value, with C and D grades being
likely to fail conservative measures. Another team described the
sedimentation sign, measured on axial MRI images to discriminate
patients with neurological claudication from asymptomatic subjects.
Our objective was to find the relationship between those two
descriptions.
Methods: 137 patients were divided in three groups: patients with
symptomatic lumbar spinal stenosis (LSS); 69 treated surgically and
41 conservatively, and low back pain (LBP) control group of 27
subjects. We studied the morphological grade of stenosis at disc level
and evidence of positive sedimentation sign.
Results: Sedimentation sign was positive in none of Grade A levels, in
58 % of grade B, in 69 % of grade C and 76 % of grade D levels. The
sedimentation sign was positive in 66 % of the surgically and in 39 % of
the conservatively treated patients and only in 8 % of the LBP patients.
Comparing LSS and LBP patients, presence of a sedimentation sign in
the LSS group had a sensitivity of 56 %, a specificity of 93 %, a positive
predictive value 97 % and a negative predictive value of 34 % (odds
ratio (OR) of 16 between those two groups). In the group of patients with
LSS who were either treated surgically or conservatively the presence
of a sedimentation sign in the surgical group carried a sensitivity of
66 %, a specificity of 60 %, a positive predictive value 74 % and a
negative predictive value of 52 %. (OR of 3.13 between the two LSS
groups). C or D morphological grades were present in 97 % of the
surgical group, in 41 % (17/41) of the conservative group and in 18 %
of the LBP group. The presence of a C or D grade was a strong predictor
of surgical treatment in the LSS group (OR 47, P \ 0.001).
Discussion: In this patient cohort presence of a C or D stenosis grade
was a stronger predictor of failure of conservative treatment than the
positive sedimentation sign. Sedimentation sign might be more useful
to identify patients to the claudicating or non-claudicating population
than for deciding which patient needs surgical treatment. Being
measured at pedicle level it is probably not suited in deciding which
levels need to be surgically decompressed.
P26
NEUROLOGICAL MANIFESTATIONS
OF THORACIC MYELOPATHY IN 203 PATIENTS
Shota Takenaka, Takashi Kaito, Noboru Hosono, Toshitada Miwa,
Takenori Oda, Shinya Okuda, Tomoya Yamashita,
Kazuya Kazuya Oshima, Kazuo Yonenobu
Orthopaedic Surgery, Osaka, Japan
Study Design: Retrospective, multi-institutional study.
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S729
123
Objective: To identify clues for the early diagnosis of thoracic mye-
lopathy by detailed investigation of the preoperative manifestations.
Summary of Background Data: Detailed investigation of the pre-
operative manifestations of thoracic myelopathy in a large population
has not been reported.
Methods: The subjects were 203 patients (142 men, 61 women; mean
age, 62.2 years; range, 21-87 years) with thoracic myelopathy who
underwent surgery at our affiliate institutions from 2000 to 2010. The
disease distribution was ossification of the ligamentum flavum (OLF)
in 106 patients, ossification of the posterior longitudinal ligament
(OPLL) in 16, OLF with OPLL in 17, disc herniation (DH) in 22,
OLF with DH in 3, and spondylosis in 39. Assessments were made of
(1) the earliest complaints and preoperative complaints, (2) neuro-
logical findings, (3) Japanese Orthopaedic Association score (full
score, 11 points), (4) the compressed segments, and (5) preoperative
duration. Multivariate analyses were performed to examine the rela-
tionships between the preoperative manifestations and causative
diseases or compressed segments.
Results: The multivariate analyses revealed relationships between:
lower limb muscle weakness and T10/11 anterior compression; low
back pain and T11/12 compression; lower limb pain and T10/11 or
T11/12 anterior compression; drop foot and T12/L1 anterior com-
pression; and hyporeflexia in the patellar tendon reflex and T11/12
compression or T12/L1 anterior compression.
Conclusions: This study demonstrated that there are characteristic
relationships between several preoperative manifestations and com-
pressed segments among a variety of symptoms caused by thoracic
myelopathy. These relationships can be helpful in the initial investi-
gation of thoracic diseases, though additional modalities such as MRI
or CT are necessary for definitive diagnosis.
P27
GENDER DIFFERENCES IN LUMBAR
DEGENERATIVE SPONDYLOLISTHESIS: IMAGE
ANALYSIS
Kosuke Tateishi, Shota Takenaka, Yoshihiro Mukai, Noboru Hosono,
Takeshi Fuji
Department of Orthopaedic Surgery, Osaka Koseinenkin Hospital,
Osaka, Japan
Introduction: The incidence of degenerative spondylolisthesis is 4
times more in women than in men. Although this gender difference
has long been recognized, the reasons underlying the difference have
not been elucidated. We performed image analysis to address this
issue.
Materials and methods: We divided 124 patients (age, more than
50 years) who underwent posterior lumbar interbody fusion for L4
spondylolisthesis between 2009 and 2011 into 2 groups: Group M (50
men) and Group F (74 women). We measured the vertebral slip (mm),
lamina inclination (degree) of L4, and intervertebral angle (degree)
between L4/5 and L5/S in flexion radiographs. The L4/5 and L5/S
intervertebral height and L5 vertebral height were measured using
computed tomography (CT), and then the ratio of the intervertebral
height to the L5 vertebral height was calculated. We also measured
the angle of the L4/5 facet joints on the CT scans, as described by
Grobler and Wiltse. Facet sagittalization was defined as the sum of
the right and left facet angles. The pre-operative clinical findings were
evaluated using the Japan Orthopedic Association (JOA) score. Sta-
tistical significance of the data was evaluated using Student’s t test. A
p value of \ 0.01 was considered significant.
Results: No significant age-related differences were observed in the
pre-operative JOA scores of the patients in Groups M and F. The
vertebral slip and lamina inclination were significantly greater in
Group F (M vs. F: 5.9 mm vs. 7.7 mm, 114.7� vs. 118.4�, p \ 0.01).
Although there was no significant difference in the ratio of the L4/5
intervertebral height to L5 vertebral height between Groups M and F,
the ratio of the L5/S intervertebral height to the L5 vertebral height
was significantly greater in Group F (0.48 vs. 0.3, p \ 0.01). There
was no significant difference in facet sagittalization between Group M
and Group F.
Discussion/Conclusion: The ratio of the L5/S height to the L5 height
was significantly smaller in Group M. This study suggested that the
degenerative change of L5-S1, which could lead to less mobility, might
promote L4 spondylolisthesis in men. In contrast, the vertebral slip
between L4 and L5 was greater in Group F, although the ratio of L5/S to L5
did not decrease. These data suggest that the pathology of spondylolis-
thesis differs in men and women. It is possible that L4 spondylolisthesis in
men is an adjacent segment disease of L5/S spondylosis.
P28
NEGATIVE BELIEFS AND PSYCHOLOGICAL
DISTURBANCE IN SPINE SURGERY PATIENTS:
A CAUSE OR CONSEQUENCE OF A POOR
TREATMENT OUTCOME?
Sina Havakeshian, Anne F Mannion
Spine Center, Schulthess Klinik, Zurich, Switzerland
Introduction: Chronic musculoskeletal pain is often associated with
psychological distress/maladaptive beliefs and these may have a negative
impact on surgical outcome. The influence of a surgical intervention, and
its outcome, on the course of change in psychological status has been
poorly documented. We prospectively examined the dynamic interplay
between psychological factors and outcome in patients undergoing
decompression for spinal stenosis/herniated disc.
Methods: Before and 12 mo after surgery, 159 patients (100 M, 59 F;
65 ± 11 y) completed questionnaires enquiring about socio-demo-
graphics, medical history, pain characteristics, psychological
disturbance, catastrophising, disability (Roland & Morris), general health
and Fear Avoidance Beliefs about physical activity (FABQ-PA). The
global outcome of surgery at 12 mo was rated using a 5-point Likert scale
and dichotomised as ‘‘good’’ (operation helped/helped a lot) or ‘‘poor’’
(operation helped only little/didn’t help/made things worse).
Results: Questionnaire data were available for 148 patients at 12mo
follow-up: 113 (76.4 %) reported a good outcome and 35 (23.6 %) a
poor outcome. In univariate analyses the following each significantly
(p \ 0.05) predicted a good 12mo global outcome: no disability
claim, and lower values for LBP frequency, average pain score,
FABQ-PA, and catastrophising. In multiple logistic regression, only
lower FABQ-PA scores (OR 0.877 (95 %CI 0.809-0.949), p = 0.001)
and lower LBP-frequency (OR 0.340 (1.249-1.783), p \ 0.0001)
significantly predicted a good outcome at 12mo. A second ‘‘explan-
atory’’ logistic regression model revealed that a good outcome at 12
mo was significantly associated with improvements (pre-op to 12mo)
in: average pain score (OR 1.6879 (1.187- 2.398), general health (OR
1.246 (1.004-1.545), psychological disturbance (OR 1.073 (1.006-
1.144), and Roland Morris (OR 1.243 (1.074-1.439).
Conclusion: In a multivariable predictive model, FABQ-PA was the
only psychological factor that significantly predicted outcome. Future
studies should assess whether preoperative cognitive-behavioural
therapy in patients with maladaptive beliefs improves treatment out-
come. Psychological disturbance did not predict outcome, but
S730 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
improved in patients with a good outcome and worsened in those with
a poor outcome. Rather than being a risk factor for poor outcome, it
appeared to be a consequence of long-standing, unremitting pain that
improved when symptoms were resolved after successful surgery.
P29
COMPLICATIONS AND RISK FACTORS
IN PATIENTS WITH AGE [ 50 AFTER SURGICAL
TREATMENT WITH INSTRUMENTATION [ 5
LEVELS: A SINGLE SURGEON EXPERIENCE
Sinan Kahraman, Gurkan Gumussuyu, Cagatay Ozturk,
Bekir Yavuz Ucar, Tunay Sanli, Wael Elkasem, Alaa Zakaout,
Azmi Hamzaoglu, Ahmet Alanay
Istanbul Spine Center, Istanbul, Turkey
Introduction: Aims were to evaluate relevance of patient’s and surgical
characteristics in development of postoperative complications following
surgical treatment of pts over age 50 and with [ 5levels of instrumen-
tation and fusion.
Methods: 137 consecutive pts (93F and 44 M), av age 67 years (50-
85) were included. All procedures performed by single surgeon in a
single center. Hospital charts were reviewed to analyze comorbidities,
intraoperative blood loss, operative time, ICU stay, hospital stay,
minor and major complications. ODI scores were used to assess
preoperative and follow up outcomes.
Results: Av f/up was 45 months (24-120). Etiologies were degenerative
spinal stenosis (111), adult scoliosis (14), spondylodiscitis (8), and
fracture (4). Sixty-six (48.1 %) patients had at least 1 comorbidity. Av
intraoperative blood loss was 2369 cc (200-8000). Av. number of
instrumented levels/patient was 7.6 (5-16)0.44 (%32.1) patients had
operations more than 10 h. Av. ICU stay was 1.82 (1-6) and hospital stay
was 19.6 (6-47) days. 46 patients (%33.5) had at least 1 prior spinal
surgery. Overall complication rate was 48.2 % including 9.49 % major
(deep infection, pneumonia, pseudoarthrosis, vascular injury) and
38.7 % minor complications (arytmia, dural tear, DVT, hematoma,
wound detachment, gastrointestinal, urinary infection, screw loosening)
0.22 (16 %) pts had re-interventions to treat complications. ODI
improved from 51.2 to 26.7 (%52.1) (p\ 0.001). Hypertension
(P = 0.001), male gender (P = 0.025) obesity (P = 0.02) and revision
surgery (P = 0.001) were risk factors for minor complications. Obesity
(P = 0.002) was found to be a risk factor for major complications.
Complications had no effects on ODI.
Conclusion: There is a high complication rate after spinal operations with
long ([5 levels) instrumentation in elderly patients ([50 years). Obesity,
hypertension, male gender and revision surgery are risk factors. However,
the outcome improves significantly despite high complication rates.
P30
PROPHYLACTIC VERTEBROPLASTY OF ADJACENT
NON-FUSED SEGMENT(S). ITS EFFECT
ON ADJACENT DISCS AND THE INFLUENCE
OF SAGITTAL MALALIGNMENT ON ITS
EFFICACY? AN MRI STUDY
Sinan Kahraman, Meric Enercan, Gurkan Gumussuyu,
Cagatay Ozturk, Levent Ulusoy, Azmi Hamazaoglu, Ahmet Alanay
Istanbul Spine Center, Istanbul, Turkey
Introduction: Prophylactic vertebroplasty (PV) has been used to
prevent failure of non-fused adjacent segment failure (ASF) over the
long-construct fusions in elderly osteoporotic pts. However, there is
still concerns that PV may not be protective against ASF if there is
sagittal malalignment after surgery. One other concern is the
decreased nutrition of the disc below the augmented level due to
cement in the vertebral body causing adjacent segment disc degen-
eration (ASD) and PJK. The aim of this study was to analyse the
efficacy of PV, its effects on adjacent discs and the effect of residual
sagittal malalignment on the success rate of PV. To our knowledge
this is the first study, analysing the adjacent discs by MRI minimum
2 years after PV procedure.
Methods: 48 (35F,13 M) elderly osteoporotic pts. (mean age
68;range 52-85) treated with minimum 5 levels instrumentation and
one or more levels PV with at least 2 years f/up (mean 42.5; range24-
70 months) were included. Amount of cement injected was 2 cc. in
upper thoracic spine and 3 cc. in lower thoracic spine. All patients
had preop and F/up ([ 2 years) MRI’s. All discs at PV levels were
evaluated in terms of disc degeneration by using Phirmann classifi-
cation. Sagital plane x-ray measurements were done to classify post-
op and f/up sagittal plane alignment according to Schwab sagittal
modifiers. PJK was determined as the cobb measurement between the
UIV and 2 levels above. All adjacent segments were analysed to
determine ASF.
Results: Av. instrumentation level was 7.35 (5-16). Av level of PV
was 1.25 (1-3). PV was performed at upper thoracic spine (T2-5) in 3
pts and lower thoracic spine in 45 pts. 60 % of pts had perfect sagittal
alignment while 40 % had abnormal sagittal alignment at f/up
according to Schwab sagittal modifiers. PJK was observed in 10 % of
pts. ASD below the PV level was observed in 20 % of pts. None of
the patients had adjacent segment collapse/fracture. There was no
correlation between the sagittal malalignment and adjacent segment
degeneration, PJK or ASF (p [ 0.05).
Conclusions: PV is effective to prevent ASF. ASD after PV below the
PV level is comparable to ASD incidence after long fusions with no PV.
Less than optimal sagittal alignment has no effect on the efficacy of PV.
P31
HOW DO ADOLESCENTS WITH IDIOPATHIC
SCOLIOSIS PERCEIVE THEIR EXPERIENCE
OF BRACING? AN EVIDENCE BASED QUESTION
Sriram Harish Srinivasan, Cheryl Honeyman
Orthopaedics and (2)South Tees Hospital NHS Trust, Leicester, UK
Introduction: Bracing is considered when the curvature of spine is
between 20� to 50�, the patient is skeletally immature and the curve is
progressing (Bono, 2007). There is level II evidence suggest that
bracing can reduce curves. Braces need to be worn full time for them
to be effective (Negrini et al., 2010), Poor compliance is strongly
correlated with brace treatment failure and appropriate support pro-
mote compliance of treatment.
Self-esteem is very unstable during early adolescence and particularly
low self-esteem has been linked to stress. We identified a lack of
support given to adolescents needing brace therapy for idiopathic
scoliosis.
The aim of the study was to explore adolescents’ feelings about their
experience of wearing a spinal brace, and their opinions on support
provided by professionals and families. There is evidence of literature
linking bracing to low body image and reduced quality of life.
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S731
123
Methods: We searched the literature for evidence and databases such
as Medline, Pubmed and Cochrane. Individual articles were looked
one by one sequentially. We reviewed wide range of publications.
Only one paper by Sapountzi-Krepia et al., 2006 was appropriate, and
appraisal of the paper was done.
Results: There is evidence available that there is lack of support given
to adolescents with idiopathic scoliosis undertaking a bracing pro-
gramme which was identified as a source of concern.
Conclusion: The evidence is to recommend changes in practice, that
ensure support to be given to adolescents undergoing a bracing pro-
gramme, including input from psychologists and regular monitoring
of patient satisfaction.
P32
DOES THE FUSION STATUS AFTER POSTERIOR
LUMBAR INTERBODY FUSION AFFECT
THE PATIENT-BASED QOL OUTCOMES? -AN
EVALUATION USING PATIENT-BASED
OUTCOME MEASURE (JOABPEQ)
Takahiro Makino, Takashi Kaito, Hiroyasu Fujiwara, Takahiro Ishii,
Kazuo Yonenobu
Department of Orthopaedic Surgery, National Hospital Organization
Osaka Minami Medical Center, Kawachinagano, Japan
Purpose: Delayed union or non-union is one of the major complications
of posterior lumbar interbody fusion (PLIF). However, little has been
known about the effect of fusion status on patients’ quality of life (QOL).
The purpose of this study was to investigate the effect of fusion status
after PLIF on patient-based QOL outcomes using Japanese Orthopaedic
Association Back Pain Evaluation Questionnaire (JOABPEQ).
Methods: A total of 57 patients (33 men, 24 women) who underwent
single level PLIF (including the patients with laminectomy combined
with PLIF at other levels) for lumbar spinal canal stenosis were
included. The mean age at the surgery was 65.3 years (range,
29-89 years). Fusion status was evaluated from dynamic lateral plain
radiographs at 6 month after surgery. Overall clinical severity was
assessed using Japanese Orthopaedic Association Score for Low Back
Pain (JOA score) before and 6 months after surgery. The patients
answered JOABPEQ (patient-based evaluation questionnaire referred
to the Japanese editions of SF-36 and the Roland-Morris Disability
Questionnaire, which consists of 25 questions and is calculated for
five functional scores for corresponding domains according to the
provided calculating formulas) before and 6 months after surgery.
The amounts of changes (postoperative scores - preoperative scores)
in all 5 subscales of JOABPEQ (low back pain, lumbar function,
walking ability, social life function, and mental health) were calculated
and compared between fusion and incomplete fusion groups.
Results: The fusion rate was 71.9 % (41 of 57 patients). The age,
gender, presences of laminectomy, number of laminectomy level,
fusion level, pre- and post-operative JOA score, or recovery rate of JOA
score were not different between fusion (n = 41) and incomplete fusion
(n = 16) group. However, the amount of changes in the subscales of
low back pain and social life function in fusion group were significantly
greater than incomplete fusion group (low back pain, 56.7 vs. 16.5,
p \ 0.01; social life function, 40.0 vs. 22.8, p = 0.01).
Conclusions: This study using patient-based QOL outcome measure
(JOABPEQ) revealed that incomplete fusion after PLIF correlated
with disability from low back pain and lack of social life function,
though the clinical severity assessed by physician (JOA score) did not
have significant correlation with fusion status. Fusion status had an
adverse impact on patients’ QOL after PLIF.
P33
A MINIMALLY INVASIVE SURGICAL APPROACH
REDUCES CRANIAL ADJACENT SEGMENT
DEGENERATION IN PATIENTS UNDERGOING
POSTERIOR LUMBAR INTERBODY FUSION
Takahiro Tsutsumimoto, Mutsuki Yui, Shota Ikegami, Masashi
Uehara, Hidemi Kosaku, Hiroshi Ohta, Hiromichi Misawa
Spine Center, Yodakubo Hospital, Nagano, Japan
Background: The multifidus (MF) muscle plays a role in lumbar seg-
mental stability. Posterior lumbar interbody fusion (PLIF) using the
Wiltse approach (minimally invasive surgery for PLIF; MIS-PLIF) does
not involve the detachment of the MF from the cranial adjacent facet
joints and spinous process; thus, this procedure has a theoretical advan-
tage over conventional open PLIF in that it reduces iatrogenic cranial
adjacent segment degeneration (ASD). To examine this hypothesis, we
compared the incidence of cranial ASD after MIS-PLIF and open PLIF.
Methods: From 2004-2006, 23 consecutive patients had undergone L4-
L5 PLIF with cages and pedicle screws (PS) through the Wiltse
approach: all procedures including cages and PS insertion were per-
formed through expandable tubular retractors placed in the gap between
the MF and the longissimus on both sides. Of the 23 patients, 1 with
Parkinsonism was excluded and the remaining 22 (mean age,
61.2 years) were retrospectively reviewed (MIS group). The mean
follow-up period was 5.7 years (range, 2-8.5 years). The open group
comprised 19 age- and gender-matched patients who had undergone
PLIF through the conventional midline approach before 2004. All
patients were followed up every 6 months after surgery. Surgical results
were evaluated using the MacNab criteria. ASD at the L3-L4 level was
assessed using plain radiography and magnetic resonance imaging,
irrespective of the presence or absence of clinical symptoms. Any
deterioration of the preoperative University of California at Los
Angeles Grading Scale or the postoperative development of stenosis,
herniation, vertebral compression fractures, spondylolisthesis, or
instability at the adjacent levels was considered indicative of ASD.
Result: Fusion was achieved in all patients in both groups. Excellent or
good outcomes were observed in 86 % (19/22) of the patients in the MIS
group. Postoperative segmental angle at the L4-L5 level was not signif-
icantly different between the 2 groups (P = 0.2). Cranial ASD developed
in 3 cases in the MIS group and in 9 cases in the open group. Kaplan–
Meier analysis showed that 94 % of the patients in the MIS group and
68 % of the patients in the open group survived for [ 3 years, while
88 % of the patients in the MIS group and 51 % of the patients in the open
group survived for [ 5 years (log-rank test, P = 0.04).
Conclusion: MIS approach potentially contributes to a lower risk of
cranial ASD in patients undergoing PLIF.
P34
CLINICAL VALUE OF RADIOGRAPHIC
SAGITTAL PARAMETERS IN ADULT SCOLIOSIS
GREATER THAN 408 FOR PATIENTS OLDER
THAN 40 YEARS
Tamara Rodriguez Lopez, Felisa Sanchez-Mariscal,
Ana Nunez-Garcia, Alejandro Gomez-Rice, Patricia Alvarez-Gonzalez,
Lorenzo Zuniga-Gomez, Javier Pizones, Enrique Izquierdo-Nunez
Spine Unit, Getafe, Spain
Introduction/Aim: Sagittal plane alignment is increasingly recog-
nized as a critical parameter in the setting of adult spinal deformity. A
S732 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
positive sagittal balance (SVA), an increased pelvic tilt (PT) and a
reduced lumbar lordosis are prognostic factors for poor clinical out-
come for adult scoliosis.
The present study was carried out in an attempt to answer this question:
In older than 40 years patients with a mainly frontal deformity (‘‘no N’’
type, Schwab 2012) what is the role of sagittal parameters?
Methods: 40 patients (35 female), 55 years old (41-74) at surgery
time. Scoliosis greater than 408 (28 idiopathic, 12 degenerative).
Mean postoperative follow-up 7.4 years.
-New full length standing radiographs were obtained and every patient
completed SRS 22 and SF36 questionnaires at the time of enrollment.
-Thoracic kyphosis (TK), Thoracolumbar Kyphosis (TLK), LL, SVA,
Spinosacral angle (SSA), Spinal Tilt (ST), pelvic sagittal parameters,
pelvic incidence-lumbar lordosis discordance (PILL)), needed lumbar
lordosis (ideal -measured) and main curve Cobb angle were measured.
Results: 1) Preoperatively an increased TLK was found (13.88), as
well a pelvic tilt near to the superior limit of the normal ranges (20.
98) and a reduced LL (LL = 488 and needed lordosis = 148).28) Through postoperative follow-up significant changes in some
radiographic parameters were identified, mainly towards a worse
sagittal profile (except TLK).
38) Patients were asked the following: ‘‘Do you think surgery was
worth it?’’ 82.5 % yes; 10 % No; 7.5 % in doubt.
48) At final follow-up there was a significant correlation (Pearson
coefficient) between the SRS activity domain an ST (p = 0.001;
r = 0.54), PT (p = 0.008; r = -0.42) and PILL (p = 0 047 r = -
0.32). After multiple linear regression only ST persisted as possible
predictor for worse SRS activity scores.
Some other less significant correlations were found.
Conclusion: Although some sagittal parameters are preoperatively
altered in adult scoliosis, they don’t seem sufficient to indicate sur-
gery, since their worsening through time does not seem to have an
impact in patient satisfaction with surgery.
-Through time, the only sagittal parameter that correlates with SRS
activity is ST.
-Sagittal plane does not seem to have a significant role as a prognostic
factor in adult patients with a mainly frontal deformity.
P35
SURGICAL TREATMENT FOR LUMBAR
DEGENERATIVE DE NOVO SCOLIOSIS
WITH SPINAL STENOSIS
Wei-feng HAN, Bao-ge LIU
orthopedic, Beijing, China
Objective: To investigate clinical effects of surgical treatment for
lumbar degenerative de novo scoliosis with spinal stenosis.
Methods: From June 2007 to January 2012, 26 patients of degener-
ative scoliosis with spinal stenosis were treated by operation, the
involved segments were determined by clinical manifestations,
radiographic documents and findings intra-operation. We carried out
posterior decompression on the segments and selected fusion on the
segments with preoperative instability or probably iatrogenic post-
operative unstable. Measured Cobb’s angle, focal lordosis angle, the
distance between C7 plumb line (C7PL) and upper edge of S1 ver-
tebral body (SVA), and the distance between C7PL and center sacral
vertical line (CSVL) after operation and final follow up were com-
pared with preoperative data. JOA score system were used to evaluate
clinical effects. The SF-36 questionary was used to evaluate the
patients’ life quality before and after operation as well.
Results: All the patients were followed up from 1.3 to 5 years with an
average of 2.5 years. Preoperative, postoperative and final follow up,
Cobb’s angle was (22.1 ± 10.5)�, (10.2 ± 7.3)�, (8.3 ± 4.8)�,
respectively; focal lordosis angle was (21.2 ± 10.3)�, (25.7 ± 12.2)�,
(31.5 ± 12.3)�, respectively; SVA was (7.5 ± 6.1) cm, (0.6 ± 3.1)
cm, (6.9 ± 5.3) cm, (-1.3 ± 2.4) cm, respectively; CSVL was
(2.7 ± 1.2) cm, (1.5 ± 1.1) cm, respectively. There was significant
difference in data before and after operation. Preoperative, instantly
postoperative, final follow up, JOA score was 10.8 ± 1.4, 21.3 ± 2.4,
23.5 ± 2.3, respectively; All domains of SF-36 score were signifi-
cantly improved postoperatively (P \ 0.05).
Conclusion: Surgical treatment with limited decompression, pedicle
screw fixation and fusion is effective method for degenerative scoli-
osis with spinal stenosis, individualized surgery design should be
made according to clinical symptoms, signs and imaging features.
Key words: lumbar scoliosis, degeneration, spinal stenosis, operation,
P36
A NOVEL CAUSE FOR CAUDA EQUINA
SYNDROME WITH A NEW RADIOLOGICAL SIGN
William Singleton, Devindra Ramnarine, Crispin Wigfield,
Nitin Patel
Department of Neurosurgery, Frenchay Hospital, Bristol, UK
Introduction: We present a case series of symptomatic, post lumbar
surgery cauda equina compression due to formation of a dissecting
subdural extra-arachnoid CSF collection (hygroma) under tension.
Surgical re-exploration and formal durotomy confirmed a tension
subdural extra-arachnoid hygroma due to one-way flow of CSF
through a pinhole puncture in the arachnoid. The diagnosis was made
surgically and is associated with a new clinically important and
pathognomonic radiological sign.
Methods: Prospective case series.
Results: In all 4 cases the MRI findings were identical. Axial images
showed central clumping of the nerve roots surrounded by a normal
CSF signal. The roots were gathered along a horizontal plane due to
lateral tethering of the dentate ligament. Surgical exploration was
successful in all cases with normal post-operative nerve function and
restoration of normal radiological anatomy.
Conclusions: Inadvertent durotomy during routine lumbar spinal
surgery is often uncomplicated if successfully repaired. However, if a
patient develops post operative diffuse lower limb or cauda equina
neurological symptoms, the rare entity of a dissecting subdural extra-
arachnoid tension hygroma should be considered in the differential.
The MRI appearances of this condition are unique and not previously
described by another group. If the diagnosis is suspected, surgical
exploration to decompress the cyst through wide opening of the
arachnoid should be considered and in this series proves successful.
ADULT THORACOLUMBAR SPINE,
NON-DEGENERATIVE
P37
ADJACENT SEGMENT INFECTION
AFTER SURGICAL TREATMENT
OF SPONDYLODISCITIS. A SERIES OF 23 CASES
AND REVIEW OF LITERATURE.
Ahmed Ezzat Siam, Heinrich Boehm
Spinal Surgery, Bad Berka, Germany
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S733
123
Purpose: First series describing and analysing adjacent segment
infection (ASI) after surgical treatment of spondylodiscitis (SD).
Methods: Retrospective review summarising clinical, laboratory and
radiological findings. All patients with primary diagnosis as spondylo-
discitis, spondylitis and/or epidural, psoas abscess have been included,
who have been surgically treated and returned to our institution with SD
of the adjacent level. Between 1994-2012, 1187 patients have been sur-
gically treated of SD in our institution; 23 patients (10 M,13F) have
returned with ASI (1.94 %), with a mean age of 65.1 years. Primary
affection was lumbar in 13 (56.5 %), thoracolumbar in 4, thoracic in 3,
cervical in one and combined thoracic and lumbar in 2. Single level
affection was found in 16 patients (65.6 %), double level in 4 and 3-levels
in 3. Five patients had epidural abscess. Mean FU was 67.6 months after
primary surgery. Comorbidities were found in 19 (82.6 %); hypertension
(12), DM (7), osteoporosis (5) and IHD (5). Mean preoperative ASA
score was 2.7 indicating poor general condition. Seven patients had
coinciding infections elsewhere.
Results: Most common primarily involved levels were L3-4 (7), L4-5
(7) and L2-3 (5), while ASI involved most commonly L3-4 (7), T12-
L1 (5) and L2-3 (4). ASI affected cranial segment in 10, caudal
segment in 10, segment between two fused segments in two patients
and adjacent segments cranially and caudally in one patient.
Mean interval between operations of primary infection and ASI was
40.9 months. All cases needed surgical intervention; debridement and
fusion with longer instrumentation; with culture-sensitivity-based
postoperative antimicrobial therapy. Mean operative time was
201 min, with a mean blood loss of 1222,9 mL. Five patients died
within postoperative six months after ASI operation (21.7 %). No
organism was isolated in 11 patients.
At last FU, Eight patients (34.8 %) were mobilised in wheelchair with
a varying degree of paraplegia. (two had preexisting paralysis).
Conclusions: ASI after surgical treatment of SD is a rare complica-
tion (1.94 %), that has been previously only as sporadic cases
reported. This is the largest series describing this phenomenon. It is
associated with multimorbid conditions. This rare complication shows
a high postoperative mortality rate (21.7 %) and a high neurological
affection rate (34.8 %). Further studies are recommended for more
analysis, prevention and treatment methods of the condition.
P38
PERCUTANEOUS KYPHOPLASTY
VERSUS CONSERVATIVE TREATMENT
IN ACUTE AND SUBACUTE OSTEOPOROTIC
VERTEBRAL COMPRESSION FRACTURES
(OVCF): A DOUBLE-BLINDED, RANDOMIZED
CONTROLLED CLINICAL TRIAL (RCT)
IN THE POPULATION OF WESTERN CHINA
Ding Jun Hao, En Xie, Qi Ning Wu
Department of Orthopedic Surgery, Hong Hui Hospital, Jiaotong
University College of Medicine, Xi’an, China
Study Design: Double-blinded, randomized controlled clinical trial
(RCT).
Objective: Clinical efficacy comparisons between percutaneous
kyphoplasty (PKP) and conservative treatment (CT) for osteoporotic
vertebral compression fractures (OVCF) are reported.
Summary of Background Data: This is the first RCT to compare
percutaneous kyphoplasty with conservative treatment in acute and
subacute osteoporotic vertebral compression fractures (OVCF) in
Chinese population.
Methods: Between July 2007 and July 2010, 164 patients with acute
(within 2 weeks) or sub-acute (2 to 8 weeks) OVCF were enrolled in
this study. They were randomly assigned to CT and PKP. In the PKP
group, there were 47 men and 30 women, aged from 57 to 77 years
(average, 67 years); In the CT group, there were 43 men and 44
women, aged from 60 to 82 years (average, 67 years). Improvement
of symptoms, restoration of vertebral body height, correction of ky-
phosis, bone cement leakage, pain, physical and psychological
outcomes were reported. Visual analog scale (VAS), SF-36 form and
the Dallas questionnaire were used to evaluate the physiological and
psychological changes of patients.
Results: The patients had an average follow-up of 9 months (from 6
to 12 months). A considerable degree of pain relief was obtained in
both groups at post-operation and 3-month follow-up (P \ 0. 05).
There was no significant difference between the 2 groups in terms of
VAS scores at either preoperation or the last follow-up (P[ 0.05).
However, a significant difference of VAS scores was observed at the
24-hour postoperation (P\ 0.05). In the PKP group, the average anterior
vertebral body height was restored by 27.9 % (P \ 0. 05) and the average
vertebral kyphosis correction was 12.6� (P \ 0.05). There were no sig-
nificant differences between the 2 groups in postoperative scores in
Health Survey Short Form (standard physical components and standard
psychological components), Dallas Pain Questionnaire (activities of
daily living, work and play, anxiety and depression, social interests),
Barthel index, Mini-Mental State Examination (P[ 0.05).
Conclusion: Compared to the CT, application of PKP for acute and sub-
acute PVCF has advantages such as immediate pain relief, early return to
active lifestyle, restoration of the vertebral body height, correction of the
kyphosis, and reduction of complication. Although CT could also
improve the symptoms after 3 to 6 months treatment, the restoration of
vertebral body height and vertebral kyphosis correction is not ideal.
Vertebral compression fracture (VCF) was one of the commonest
cause osteoporosis fractures. There are over 700,000 VCF patients
yearly. Percutaneous kyphoplasty, PKP was a minimally invasive
surgical approach that uses interventional radiology technique and
involves the fluoroscopically guided injection of polymethylmeth-
acrylate (PMMA) through a needle inserted into a weakened
vertebral body. PKP and conservative treatment of the controversy
was big focus disputed problem by medical expert. In China, there
was no randomized controlled study reported in this regard. It was
still controversial to choose between PKP and conservative treat-
ment for VCF patients. In this study, we treated 164 osteoporotic
VCF (OVCF) patients with either PKP or CT method under a
double-blinded, randomized controlled study between July 2007 and
July 2010. In china, this study was Level I evidence according to
U.S. Preventive Services Task Force. The results were reported below.
Keywords: Osteoporotic vertebral fractures, kyphoplasty, PKP,
conservative treatment, randomized study
P39
A PROSPECTIVE STUDY OF PERCUTANEOUS
BALLOON KYPHOPLASTY WITH CALCIUM
PHOSPHATE CEMENT IN TRAUMATIC
VERTEBRAL FRACTURES: 10 YEARS RESULTS
Gianluca Maestretti, Patrick Sutter, Riccardo Ciarpaglini,
Monnard Etienne, wahl Peter, Emmanuel Gautier
Department of Orthopaedic Surgery, Spinal unit, Fribourg,
Switzerland
Study design: This is a a prospective study to investigate the clinical
and radiological results 10 years after percutaneous balloon
S734 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
kyphoplasty and cement augmentation with Calcium Phosphate
Cement (CPC) in traumatic vertebral fractures type A.
Objectives: Evaluation of a 10 year follow up with radiological and
computed tomography results, calculated by 2 independent radiolo-
gists, VAS, Roland Morris score, ODI score and Denis work scale and
clinical examination in patients with traumatic compression fractures
type A, who were treated with a balloon kyphoplasty with CPC
(CalcibonTM; from Biomed).
Methods: In this study we evaluated 21 patients (8 female and 13
male) clinically and radiologically 10 years postoperative and com-
pared them with the same group of 28 patients we operated between
August 2002 and August 2003 for traumatic vertebral fractures type A
with balloon kyphoplasty and CPC. Over the 10 years 7 patients were
untraceable. 3 of them were not clinically impaired but didn’t want to
participate in the study and 4 patients we didn’t found. All 21 patients
underwent standard X-ray (standing) and a CT. We measured the
volume of the cement, the resorption the last 10 years and the disc
height in the CT and the segmental and vertebral kyphosis angle in the
X ray and compared them with the X-ray (standing) and CT done
directly postoperatively. To assess the pain level we used the VAS,
ODI score, Roland Morris score and the Denis work scale and
compared them with the same scores we recorded in the past.
Results: The VAS score demonstrated an increase over time from a
mean of 1 (0-5) at the 2 year follow up to 2.3 (0-8) at the 10 years
follow up. The Roland Morris disability score also increased over
time from 2 (0-8) 2 years postoperative to a mean of 3.6 (0-18) at the
10 years follow up. We recognized no complications and no reoper-
ations were necessary.
We recognized an increase of the median value for the vertebral
kyphosis angle about 1� (0� - 4�). The median value of the disc height
diminution over the 10 years was 0.7 mm (0 - 3.9). For the anterior
wall of the fractured VB the decrease of the median value was about
1 mm (0-3) and for the posterior wall it was 0 mm (0-2). So the Beck
Index decreased from 0.80 (0.65 - 0.97) to 0.77 (0.62 - 0.97) at the
10 year follow up which means a decrease of the median value of
0.03 (0 - 0.07). We noticed a median value for the cement volume of
4.2 cc (2.0-8.6) postoperative and at the 10 year follow up of 3.2 cc
(1.3-7.8) which means a resorption of the cement volume about
22.9 % (0.8 % - 55.5 %).
Conclusions: In our 10 year follow up we didn’t recognize any sig-
nificant loss of correction of the vertebral and segmental kyphosis
angle. We also didn’t recognized a significant diminution of the disc
height without degeneration of the disc over the last 10 years. There
was a partial resorption of the cement but not as much as we expected
with variable bone formation. In summary the long follow up about
10 years of kyphoplasty show us very good clinical and radiological
results and in our opinion we consider this to be a treatment option for
traumatic selected vertebral type A fractures also in young patients.
P40
MOTOR FUNCTION OF LOWER EXTREMITIES
AFTER TOTAL EN BLOC SPONDYLECTOMY
WITH SACRIFICE OF BILATERAL L2 NERVE ROOTS
Hideki Murakami, Satoru Demura, Satoshi Kato, Katsuhito Yoshioka,
Hiroyuki Hayashi, Kazuya Shinmura, Noriaki Yokogawa,
Xiang Fang, Hiroyuki Tsuchiya
Department of Orthopaedic Surgery, Graduate School of Medical
Sciences, Kanazawa University, Kanazawa, Japan
Introduction: During total en bloc spondylectomy (TES), the nerve
root is often sacrificed to perform en bloc corpectomy. Preservation of
the nerve root requires wide lateral exposure or posterior-anterior
combined surgery. According to the strategy adopted at our institute,
the L2 and upper nerve roots are sacrificed and the L3 and lower
nerve roots are preserved during TES of the lumbar spine. However,
since sacrificing the L2 root also affects the branch to the femoral
nerve, the effect on femoral nerve motor dysfunction is uncertain.
This study aimed to investigate the relationship between L2 root
sacrifice and postoperative leg motor function.
Patients and methods: Ten patients (6 men, 4 women; mean age,
49.3 years) who underwent TES with sacrifice of bilateral L2 roots were
included. The motor function of the lower extremities was determined
using a modified Frankel classification and Manual Muscle Testing
(MMT) of iliopsoas (IP) and quadriceps femoris (QF) preoperatively,
1 week post-surgery, 1 month post-surgery, and on the last follow-up
day. The results from the weaker side were used when MMT showed a
laterality difference.
Results: The preoperative IP MMT score decreased to 4 in 1 patient;
however, the Frankel classification was D3, meaning she had no gait
disturbance. Compared with preoperative investigation, at 1 week post-
surgery, IP MMT was the same in 3 patients, decreased by 1 point in 6
patients, and decreased by 2 points in 1 patient, and QF MMT was the
same in 4 patients, and decreased by 1 point in 6 patients. Compared
with preoperative investigation, at 1 month post-surgery, IP MMT was
the same in 6 patients and decreased by 1 point in 4 patients, and QF
MMT at 1 month post-surgery was the same in 9 patients and decreased
by 1 point in 1 patient. On the last follow-up day, IP MMT decreasing
remained in 3 patients, and QF MMT improved in all patients. The
Frankel classification was E in 3 patients, D3 in 1 patient, and D2 in 6
patients 1 month post-surgery, and E in 6 patients and D3 in 4 patients
on the last follow-up day. No patient had gait disturbance.
Conclusion: All patients whose bilateral L2 roots were sacrificed
during TES were able to walk without assistance, although mild
weakness of IP remained in 3 patients. Although the MMT of IP and
QF may be slightly affected by L2 roots sacrifice, it should be noted
that walking function remains intact. Sacrifice of L2 roots appears to
be an acceptable procedure in TES.
P41
PREVENTION OF SURGICAL SITE INFECTION
USING IODINE-COATING SPINAL INSTRUMENTS
Hideki Murakami, Toshiharu Shirai, Satoru Demura, Satoshi Kato,
Katsuhito Yoshioka, Hiroyuki Hayashi, Takashi Ota,
Kazuya Shinmura, Noriaki Yokogawa, Hiroyuki Tsuchiya
Department of Orthopaedic Surgery, Kanazawa, Japan
Introduction: Surgical site infection (SSI) associated with spinal
instruments remains a serious complication in spine surgeries. We
newly developed antimicrobial coating spinal instruments for pre-
vention and treatment of spinal infection. This instrument has
povidoneiodine-containing surface. In basic study using white rabbits,
iodine-coating titanium has antibacterial activity, biocompatibility,
and no cytotoxicity. We have performed a clinical trial of iodine-
coating spinal instruments which suppress microbial activities of
bacteria, virus and fungus. Our purpose is to evaluate the effective-
ness of iodine-coating spinal instruments for preventing SSI.
Methods: We have treated 122 compromised patients under immu-
nosuppressive condition such as cancer (96 cases), hemodialysis (8
cases), diabetes (7 cases), steroid administration (4 cases), and so on,
using iodine-coating instruments to prevent SSI. The age of the
patients was 55.2 years (range, 18-75 years) on average. Sixty-four
patients were male and 58 were female. To confirm whether iodine
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S735
123
from the instruments influenced the body, thyroid hormone levels in
the blood were examined. After the operation radiological evaluations
were performed regularly.
Results: SSI was perfectly prevented in 119 of 122 compromised
hosts except for 3 cases. In one case with a huge synovial sarcoma of
back, wide excision of the tumor with latissimus dorsi flap was per-
formed. However, SSI occurred around polypropylene mesh for chest
wall reconstruction after postoperative intensive chemotherapy. After
exchange of the mesh, SSI was cured. In one case with gastric cancer
metastasis at L4, SSI occurred after total en bloc spondylectomy.
However, SSI was cured by antibiotics only without revision surgery.
In the other case which had decompression and stabilization surgery
for multiple spinal metastases from breast cancer, SSI was cured by
curettage and irrigation. In all 3 cases, SSI was cured without removal
of instruments. Abnormalities of thyroid gland function and instru-
mentation failure were not detected.
Discussion and Conclusion: We newly developed a procedure for the
anodization of iodine-containing surfaces that can be directly-coating
to existing titanium implants, and iodine-coating spinal instruments
were invented. The iodine-coating spinal instruments had a great
effect on preventing SSI in compromised patients. Moreover, there
were no cytotoxicity and adverse effects detected.
P42
TEMPORARY PEDICLE SCREW FIXATION
WITHOUT AUGMENTATION
FOR THORACOLUMBAR BURST FRACTURES
Hiroyuki Aono, Hidekazu Tobimatsu, Yukitaka Nagamoto
Orthopedic Surgery, Osaka, Japan
Introduction: Short-segment posterior spinal instrumentation for
thoracolumbar burst fracture has its merit based on superior correc-
tion of kyphosis by indirect reduction technique. However, failure of
this procedure in loss of kyphosis correction has been frequently
reported. As the materials and configuration of spinal instrumentation
advanced considerably compared with the research period of these
failure reports, we performed this procedure without augmentation.
Methods: This study included 24 consecutive patients with thoraco-
lumbar burst fracture (T11-L3) who underwent surgery by
ligamentotaxis procedure using Schanz screws without augmentation.
Their implants were removed around 1 year after operation after
confirming union of the fracture. We have measured local vertebral
body angle (VBA) and superior-inferior endplate angle SIEA) before
and just after operation, approximately 1 year after initial operation
and 6 to 12 months after removal. We also evaluated fracture severity
according to load sharing classification.
Results: Operation was performed 0 to 9 (mean 3.5) days after injury.
Mean operating time was 100 min and mean blood loss was 131 ml. After
surgery, all 11 patients with neurologic deficit had improvement equiva-
lent to at least one ASIA grade. One patient had screw breakage 8 months
after operation but collapse of injured vertebra was not accelerated.
VBA was corrected from 17.3� before surgery to 6.5� after surgery. Loss
of correction was 0.5� before removal, which deteriorated by another 0.2�after removal. Total loss of correction was 0.7� from the initial surgery.
SIEA was corrected from 13� before surgery to 1� after surgery. Loss of
correction was 2.2� before removal, which deteriorated by another 7.6�after removal. Total loss of correction was 9.8� from the initial surgery.
Taken together, these results indicate that postoperative kyphotic
change was related to disc level not fractured vertebra; maintenance
of reduced vertebral body height was successful regardless of load
sharing classification.
Conclusion: Temporary short-segment fixation without augmentation
yielded satisfactory results. Maintenance of fractured vertebra was
independent of load sharing classification. Kyphotic change was
observed due to loss of disc height mostly after removal of implants.
Such change might be inevitable, as adjacent discs can be injured at
the onset. Kyphotic change may thus be a limitation of this surgical
procedure.
P43
EVALUATION OF THE INTERVERTEBRAL DISC
IN TYPE A THORACOLUMBAR FRACTURES
Hugues Pascal-Moussellard, Philippe Loriaut, Guillaume Mercy,
Patrick Boyer, Yves Catonne
Department of Orthopaedic Surgery, Hospital Pitie Salpetriere,
PARIS, France
Introduction: Despite a sizable amount of literature, the optimal
management of thoracolumbar fractures remains controversial. Many
authors assume the existence of disc lesions in Magerl type A frac-
tures. The aim of this study was to assess changes in the intervertebral
discs adjacent to type A thoracolumbar fractures.
Methods: 56 patients with 95 type A thoracolumbar fractures were
studied with a median follow-up of 25 months (range 18-37). The
patients received conservative or surgical treatment during four years at
our institution. Radiological assessment included CT-scan and MRI
realized initially, then within 1 week of trauma and at final follow-up.
CT-scan study involved characterization of Magerl/AO subtypes frac-
tures, measurements of adjacent vertebral body and disc heights in
millimeters. MRI was performed for the evaluation of disc signal, height
and morphology modifications and compared to Oner classification.
Results: Mean disc height was 1.03 ± 0.36 initially, 0.98 ± 0.23
after treatment and 0.97 ± 0.35 at last follow-up. Mean vertebral
height was 0.88 ± 0.2 initially, 0.86 ± 0.26 after treatment and
0.85 ± 0.24 at last follow-up. No signal intensity modification was
identified. Disc morphology was either normal or altered with redis-
tribution of discal tissue in the vertebral end-plate depression. Mean
values and observations did not differ at last follow up.
According to Oner, 38 suprajacent discs were type 1, 1 was type 2, 25
type 3, 1 type 4 and 1 type 5. All subjacent discs were type 1 except
from 12 discs which were cranial to a second fracture corresponding
type 3 pattern.
Conclusions: In this study, CT-scan imaging showed that no loss of
height occurred in adjacent discs to fractured vertebra whereas there
was a vertebral end-plate depression, more important in A3 than in
A1. MRI showed no major alteration of the intervertebral disc in
terms of signal intensity and morphology.
P44
THE PREDICTIVE VALUE OF THE SPINAL
INSTABILITY NEOPLASTIC SCORE (SINS)
SYSTEM FOR ADVERSE EVENTS
OF PATHOLOGIC FRACTURE AND SPINAL CORD
COMPRESSION IN PATIENTS WITH SINGLE
SPINAL METASTASIS
Hyoungmin Kim, Choon-Ki Lee, Jin S. Yeom, Jae-Hyup Lee
Department of Orthopaedic Surgery, Seoul, Korea (ROK/South
Korea)
S736 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Introduction: The SINS, developed to assess the spinal instability in
patients with metastatic spinal tumor, seems to have a potential pre-
dictive value for the adverse event of pathologic fracture (Fx) and
epidural spinal cord compression (ESCC). This study was performed
to evaluate the predictive value of the SINS system for spinal adverse
events in patients with a single spinal metastatic tumor.
Methods: The pain, location, quality of bone lesion, spinal alignment,
collapse of vertebral body, involvement of posterior spinal elements
were assessed according to the SINS system for a consecutive series
of 78 patients with a single spinal metastasis. The attribution of the
each and total score of the SINS was assessed to the spinal events of
Fx and ESCC after detection of spinal metastasis by Cox proportional
hazard model.
Results: Average age of patients when the primary disease was
diagnosed was 55 years and they lived mean of 43 months after the
diagnosis. Spinal events occurred at the mean of 8 months after
diagnosis of the primary disease. Gastrointestinal system was the
most common site of primary disease and breast was the second one.
The survival after the diagnosis of the spinal metastasis was different
according to the primary cancer: patients with breast cancer lived for
mean of 6.5 years and for only 0.5 years with lung cancer since the
detection of the spinal metastasis. Cox regression analysis found that
the pain (p = 0.008) and posterior involvement score (p = 0.002)
was significantly related with the event of ESCC. The scores of the
pain (p = 0.009), alignment (p = 0.008) and location (p = 0.036)
were also related with the event Fx. With the higher score in the
related components was related with higher rate of spinal adverse
events except for the location components. Lesions in mid-thoracic
location (1 point of the SINS) showed higher hazard ratio of Fx than
the mobile spine (2 points) or junctional area (3 points). The sum of
SINS was not related with the spinal adverse events.
Conclusion: Among the components of the SINS system, the
mechanical pain, location, and alignment showed significant corre-
lation with the event of Fx, and with the event of ESCC, mechanical
pain and posterior involvement were related in patients with single
spinal metastasis.
P45
A RETROSPECTIVE ANALYSIS INVESTIGATING
THE CAUSES OF NEUROLOGICAL DEFICITS DUE
TO OSTEOPOROTIC VERTEBRAL FRACTURES
Itaru Oda, Eihiro Murota, Hirohito Takeuchi, Shigeki Oshima,
Masanori Fujiya
Department of Orthopaedic Surgery, Hokkaido Orthopaedic
Memorial Hospital, Sapporo, Japan
Purpose: To select appropriate treatments for osteoporotic vertebral
fractures, the causes of neurological deficits must be understood. The
purpose of this study was to investigate the causes of neurological
deficits associated with osteoporotic vertebral fractures.
Methods: A total of 83 patients who underwent surgeries for neu-
rological symptoms associated with osteoporotic vertebral fractures
were reviewed. There were 65 female and 18 male patients with an
average age of 74.9 years. Intraoperative findings, neurological and
radiographic examinations were reviewed and the responsible region
for neurological symptoms was detected. Neurological symptoms
were categorized into myelopathy, cauda equina syndrome, and
radiculopathy. Also, causes of neurological symptoms were classified
into two types including ‘‘Compression’’ and ‘‘Instability’’. The
Compression type was defined as neurological symptoms with neural
compression on the MRIs, and the symptoms did not improve by
preoperative bed rest. The Instability type was defied as neurological
deficit with slight or no neural compression on the MRIs, and it
improved by preoperative bed rest.
Results: Fifty-five of 83 patients presented myelopathy. Thirty-three
of them (62 %) were Compression type. Four patients indicated
preexisting spinal cord compression at the segment above the fracture,
and delayed myelopathy was detected during conservative treatments.
Twenty patients of myelopathy (38 %) were Instability type and all
patients showed intravertebral cleft. Thirty of 83 patients presented
cauda equina syndrome or radiculopathy. Twenty-seven of them
(90 %) were Compression type, while 3 cases (10 %) were Instability
type. Only four patients demonstrated radiculopathy at the neural
foramen, and all four cases showed neural compression by the lower
endplate fracture.
Conclusions: In approximately 40 % of myelopathy cases, instability
was the main pathology and surgical treatments should be stabiliza-
tion without decompression. As a preexisting spinal cord compression
at the level above the fracture may result in progressive myelopathy,
conservative treatments must be carefully performed even if the
patient is neurologically intact. In 90 % of the patients with cauda
equina syndrome or radiculopathy, neural compression was the main
pathology and stabilization with decompression should be considered.
Although not common, foraminal stenosis should be assessed in case
of lower end-plate fractures.
P46
TWO-YEAR CLINICAL AND RADIOLOGICAL
OUTCOMES IN A PROSPECTIVE COHORT
OF PATIENTS WITH VERTEBRAL FRACTURES
Javier Pizones, Lorenzo Zuniga, Patricia Alvarez-Gonzalez,
Felisa Sanchez-Mariscal, Enrique Izquierdo
Spine Unit, Department of Orthopaedic Surgery. Hospital
Universitario de Getafe, Madrid, Spain
Introduction: The aim of the study was to prospectively evaluate the
2-year clinical and radiologic results in a cohort of patients with acute
thoracolumbar fracture.
Materials and methods: Patients hospitalized during a two-year
period for an acute traumatic thoracolumbar fracture, excluding
pathological fractures, were prospectively included in the study. An
analysis was performed with age, gender, AO fracture type, type of
treatment, and local and regional kyphosis (preoperative and 1 month
postoperative). At 2 years, the following data were collected: local
and regional kyphosis, SF-36 and Oswestry Disability Index (ODI)
results, and complications. A comparative study was performed
between the conservative group and surgical group using the Chi
square and Mann–Whitney U tests.
Results: Thirty-one patients were included in the study, 3 were lost to
follow-up; response rate 90.3 %. Total sample description was as
follows: 50 % were males; mean age 39.8 ± 14.4 years; fracture
localization was: 21 % thoracic area, 71 % thoracolumbar, and 8 %
lumbar; L1 was the most often affected level (32 %); according to the
AO classification: 53 % were type A, 39 % type B, and 8 % type C.
Surgical treatment was used in 50 % (Sx Group), the majority by
posterior instrumented fusion; the other half were managed conser-
vatively (C Group).
Statistically significant differences (p \ 0.05) were found for local
preoperative kyphosis (C: 12.28 ± 3.7 vs Sx: 17.68 ± 4); local
kyphosis at 1 month (C: 12.58 ± 3.2 vs Sx: 6.48 ± 5.4); and final
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S737
123
local kyphosis (C: 14.88 ± 6.8 vs Sx: 6.48 ± 6.6). At the end of
follow-up, patients undergoing conservative management showed a
+3.18 ± 4 increase in kyphosis, whereas those with surgical treatment
showed a -11.28 ± 0 (63 %) correction.
At two years there was a non-significant trend favoring conservative
treatment in all SF-36 domains except emotional role (Table).
Patients who underwent conservative treatment showed less final
disability on the ODI (C: 13.5 % vs Sx: 29.8 % p = 0.006).
Two conservatively treated patients had a [ 208 increase in kyphosis
at final follow-up and one required surgery. In the Sx group, the
reoperation rate was 28 %.
Conclusion: Patients with stable fractures treated conservatively had
residual kyphosis, but an acceptable quality of life. In patients with
unstable fractures that required surgical fixation, normal kyphosis was
restored, but the clinical outcome was less satisfactory.
P47
RADIOLOGICAL RESULTS OF SHORT SEGMENT
INSTRUMENTATION AND FUSION IN TYPE C AO
THORACOLUMBAR FRACTURES
Jose Fleiderman, Sergio Ramırez, Alberto Telias, Javier Lecaros,
Francisco Ilabaca, Alejandro Urzua, Juan Zamorano,
Vicente Ballesteros, Ratko Yurac, Miguel Lecaros
Traumatologia, Santiago, Chile
According to Magerl’s classification, type C thoracolumbar spine frac-
tures are those produced by rotational and shearing mechanisms,
affecting both columns. This type of injuries require surgical treatment in
order to achieve decompression of the neural structures together with
fracture reduction and stabilization through spinal instrumentation until
spinal fusion occurs. Traditionally, long segment instrumentations and
fusions have been used in the treatment of these lesions. Short segment
instrumentations are those including, at the most, one segment above and
one below the injured one. Monosegmental instrumentations represent
the maximum preservation of moving spinal segments. In this way, we
consider that knowledge about the radiological evolution, both in the
short and long term, of this short instrumentations and fusions is very
useful, as it can further validate them in the management of these patients
with highly unstable spine fractures. The objective of this study is to
evaluate the radiological results, by establishing the failure rate, of short
segment instrumentations and fusions in the treatment of patients with
type C AO thoracolumbar fractures.
Materials and Methods: Retrospective case series of 31 patients with
type C AO thoracolumbar spine fractures, operated at our institution
with a short segment instrumentation and fusion (bisegmental or
monosegmental), with a minimum follow-up of 2 years. Those
patients who required a complimentary anterior fusion and/or those
who used a brace during follow-up were excluded. Hardware fracture,
loosening and/or progression of segmental kyphosis of 108 or more
were considered as failure of the instrumentation.
Results: Patients’ mean age at the moment of surgery was 39 years.
Forty-one percent of the patients presented subtype C3 AO fractures,
29 % subtype C2 and 29 % subtype C1. The mean progression of the
segmental kyphosis in the study group was 4.58, and only three
patients presented instrumentation failure during follow-up, according
to the previously described criteria: two cases of hardware fracture,
while one patient evolved with progression of 108 of the segmental
kyphosis.
Conclusion: The use of short segment instrumentations and fusions in
the treatment of type C AO thoracolumbar spine fractures is a suitable
alternative in selected patients. In our case series, we report a failure rate
of 9.6 %.
P48
THE CLINICAL IMPORTANCE OF POSTERIOR
VERTEBRAL HEIGHT LOSS IN OSTEOPOROTIC
VERTEBRAL FRACTURE
Jun-Yeong Seo, Kwang Woo Nam, Sungwook Choi, Kee-Yong Ha,
Kyu Bum Seo
Orthopaedic surgery, Jeju, Korea (ROK/South Korea)
Introduction: In patients with vertebral fracture, the height loss of the
fractured vertebra occurred inevitable after starting ambulation, even
if they wear orthosis. The pulposes of this study is to investigate the
correlation of the posterior height loss with vertebral canal
compromise.
Materials and methods: From June 2010 to January 2012, patients
who suffered from thoracolumbar vertebral fractures were investi-
gated. After 2 weeks of bed rest, tolerable ambulation was permitted
in wearing custom molded orthoses. Orthoses were kept for 12 weeks.
Radiological assessment including anterior, posterior height of ver-
tebral body of affected level and superior and inferior adjacent level
were measured at initial, 2, 4, 6, 12 weeks, 6 months, 9 months,
12 months. The height loss(%) were calculated from the estimated
loss of fractured vertebral height by the mean of superior and inferior
vertebrae. Magnetic resonance imaging (MRI) were performed to
assess vertebral fracture. The MRI findings of fractured vertebrae
were divided to 3 types by enhancing pattern. In patients with sig-
nificant height loss in follow up x-ray were evaluated by computed
tomography(CT) or MRI.
Results: 97 patients were enrolled for this study. 15 patients were
male, 82 patients were female. Mean age at initial visit were
70.25 ± 14.6. The mean t-score of lumbar spine was -2.95 ± 1.03.
At initial visit, the average anterior height loss was 25.2 ± 3.5 % and
the average posterior height loss was 7.78 ± 2.1 %. 42 out of 97
patients showed posterior vertebral body involvement. The mean
canal encroachment at initial visit was 11.79 ± 4.9 %. MRI findings
showed 16 cases of type 1(17 %), 68 cases type 2(70 %) and 13 cases
of type 3(13 %). During the follow-up period, significant posterior
height loss was noticed in 32 patients and CT or MRI was performed
to evaluated canal encroachment. Newly developed canal encroach-
ment was found in 8 patients. The mean canal encroachment was
15.3 ± 7.6 %. Of them, neurologic complication was found in 4
patients. All of the 4 cases showed type 3 MRI pattern at initial.
Conclusions: In thoraco-lumbar vertebral fractures, the posterior
vertebral body height loss was important findings during follow up
period, because they usually followed by spinal canal encroachment.
In patients with simple compression fracture, great attention to the
posterior vertebral height should be paid to detect the spinal canal
compromise which could be followed by devastating result.
P49
SURGICAL MANAGEMENT FOR SPINAL CORD
INJURY IN PATIENTS WITH ANKYLOSING
SPINAL DISORDERS
Kazuhiro Takeuchi
Orthopaedic Surgery, National Okayama Medical Center, Okayama,
Japan
The ankylosing spinal disorders include ankylosing spondylitis (AS),
ankylosing spinal hyperostosis (ASH) and diffuse idiopathic skeletal
S738 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
hyperostosis (DISH). AS is a chronic rheumatic disease. Bone for-
mation around paraspinal structure reduces bone mineral and bone
quality of vertebra. AS is a great risk factor for spinal fracture because
of mechanical stress due to loss of spinal flexibility and bone fragility.
Minor trauma can easily lead to spinal fracture with subsequent
severe spinal cord injury (SCI). The purpose is to discuss about the
specific features of AS fracture and review the surgical outcomes.
We report 24 AS cases (mean age: 75.7 yrs.) with SCI following
spinal fracture. This study was composed with clinical and image
analysis. The clinical records were retrospectively reviewed about
pain status and neurological functions.
CT and MRI showed great view of fracture. MRI identified 3-columns
injury including both transdiscal and transvertebral.
Thoracolumbar spine was most commonly affecting level in 17/24
cases. Low energy trauma caused SCI in 16 cases. Neurological
deficits were revealed in 20 cases (ASIA A:1, B:3, C:10, D:6). 13
patients (65 %) had delayed diagnosis or late onset neurological
deficits before admission.
Posterior fusion was performed in 17 cases. Pedicle screw fix-
ation was convenient. However these screws were not enough to
control spinal instability due to bone fragility. Image analysis
revealed two nonunion cases. Screw loosening and pull out was
detected in 8/17 cases. We applied supplemental procedures
using sublaminar wiring to secure fixation. A successful stabil-
ization required a combined anterior and posterior fusion for 7
delayed union cases.
Surgical outcomes were reliable in this series. Back pain was reduced
in all cases. Neurological improvement was shown in 8/20 cases.
However there was no improvement in severe paraplegic cases. No
patient experienced neurological deterioration with surgery.
Spinal fracture in AS is unique and different from common fracture.
The fracture always extends completely across the vertebral segment
leading to unstable 3-column injury. It requires careful imaging
assessment and aggressive surgical management to prevent secondary
neurological deterioration. Multilevel screw fixation is one of the
great options. The correction is essential for this maneuver. Open
wedge is prohibited at fracture site. Sublaminar wiring or banding and
massive bone graft is a key to get solid fusion.
P50
ARE PERCUTANEOUS PEDICLE SCREWS MORE
ACCURATE THAN OPEN?
Matthew George Stovell, Martin Wilby, Chris Barrett
Neurosurgery, Liverpool, UK
Objective: To assess the accuracy of pedicle screw insertion by five
spinal surgeons in a regional neurosciences centre and compare
results using the open and percutaneous technique.
Methods: All pedicle screws inserted between March 2011-2013
were recorded on a prospectively collected database (Spine Tango) by
five spine specialist consultants using systems from three major
companies. Pathology included trauma, malignancy and degenerative
spine disease. Open screws were inserted using anatomical land-
marks, pedicle probing and biplanar fluoroscopy. Percutaneous
screws were inserted using biplanar fluoroscopy alone. 3D image
guidance was not used. Accuracy was assessed using the Zdichavsky
scoring system 1 on post-operative CT imaging when available.
Zdichavsky 1a was considered optimal; 1b & 2a acceptable, 2b & 3a
poor and 3b very poor.
Results: 163 patients were included on the database. Post-operative
CT imaging was performed on 89(55 %). 66 of these had an open
procedure and 23 underwent percutaneous fixation. Optimal screw
position was achieved in 85.5 %(283) of the open screw insertions
and 88.8 %(87) of percutaneous screw insertions (not statistically
significant, p = 0.408 Fisher’s Test). An acceptable position was
attained in 8.2 %(28) of the open group and 8.2 %(8) of the percu-
taneous group. Of the open group, 5.1 %(14) were poor and 0.9 %(3)
were very poor. Of the percutaneous group, 3 %(3) were poor and
none were very poor.
Conclusions: The accuracy of pedicle screw insertion in both groups
was comparable to that reported previously in the literature1.
Although it did not reach statistical significance, our series may
suggest greater accuracy of pedicle screw placement using a percu-
taneous technique rather than an open technique. Importantly, there
were no percutaneous screws inserted with a ‘very poor’ trajectory
(Zdichavsky 3b). We advocate the use of percutaneous fixation of the
thoracic and lumbar spine for trauma, malignancy and degenerative
spinal disorders.
References: 1 Zdichavsky M et al. Accuracy of Pedicle Screw
Placement in Thoracic Spine Fractures Part I. Eur J Trauma 30:234-
240, 2004
P51
RISK FACTORS FOR POSTOPERATIVE
CEREBROSPINAL FLUID LEAKAGE
ASSOCIATED WITH TOTAL SPONDYLECTOMY
Noriaki Yokogawa, Satoru Demura, Murakami Hideki, Satoshi Kato,
Katsuhito Yoshioka, Hiroyuki Hayashi, Takashi Ota,
Kazuya Shinmura, Xiang Fang, Hiroyuki Tsuchiya
Department of Orthopaedic Surgery, Graduate School of Medical
Sciences, Kanazawa University, Kanazawa, Japan
Introduction: Cerebrospinal fluid (CSF) leakage is a serious post-
operative complication associated with spine surgery. CSF leakage
can lead to surgical site infection, pyogenic meningitis, intracranial
hypotension, and prolonged hospitalization. In total spondylectomy,
the dura mater is dissected circumferentially. Therefore, great care
must be taken to prevent CSF leakage after total spondylectomy. In
this study, we examined the incidence and risk factors for CSF
leakage after total spondylectomy.
Patients and Methods: A total of 70 patients underwent total
spondylectomy between May 2010 and February 2012. Of the 70
patients, 63 were selected for the study, and 7 patients with dural
injury during operation were excluded. The patients included 35 men
and 28 women with a mean age of 53.7 years (range, 16-75 years) at
the time of surgery. We examined the association between postop-
erative CSF leakage and the following parameters: age, sex, smoking,
diabetes, radiotherapy at the surgical site, chemotherapy, revision
surgery, surgical level of the spine, surgical approach, number of
vertebral bodies resected, and number of nerve roots sacrificed. We
also assessed the course of treatment for CSF leakage in each patient.
In this study, C 250 ml/day of serous drainage after postoperative
day 5 was defined as postoperative CSF leakage.
Results: Postoperative CSF leakage was observed in 11 of the 63
patients (17.5 %). Our multivariate analysis demonstrated that
radiotherapy at the surgical site was a significant risk factor for
postoperative CSF leakage. Six of 15 (40 %) of patients with a history
of radiotherapy experienced postoperative CSF leakage. An age of
more than 60 years was a significant risk factor in the univariate
analysis but not in the multivariate analysis. Eight of 27 (29.6 %)
patients aged more than 60 years experienced postoperative CSF
leakage. Although all 11 patients with CSF leakage were treated using
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S739
123
factor XIII concentrate, 1 patient required reoperation. This patient
had a history of radiotherapy at the surgical site.
Discussion and Conclusions: The incidence of postoperative CSF
leakage associated with total spondylectomy was 17.5 %. Among
patients with a history of radiotherapy at the surgical site, this inci-
dence was particularly high (40.0 %). Our results suggest that
irradiation may result in histological changes, such as increased
permeability and fragility of the dura mater, which contribute to the
high incidence of CSF leakage.
P52
DOES GERIATRIC STATUS IMPACT
THE PRESENTATION AND MANAGEMENT
OF ACUTE FRACTURES OF THE
LUMBAR SPINE?
Osa Emohare, Alison Dittmer, Robert Morgan, Julie Switzer
Department of Orthopaedics, St Paul, USA
Introduction: The frequency of lumbar spine surgery has increased
by an order of magnitude over the last 20 years. This increase has
been particularly marked in geriatric patients. Specific changes in the
spine are known to be associated with the process of aging. While the
majority of fusions occur for degenerative disease, a relatively non-
controversial indication for fusion is trauma to the lumbar spine.
Given the physiological differences associated with aging, we sought
to review the impact of age on the patterns, management and out-
comes of acute lumbar fractures.
Methods: Following IRB approval, all patients who had presented with
acute fractures involving any of their lumbar vertebrae were identified.
We collected details of consecutive patients presenting to a level I
trauma center with between June 2010 and December 2012. Patients
were stratified into an index population (18 and 64 years) and a study
population ([ 65 years) and comparisons were made between both
groups.
Results: A total of 88 patients were reviewed; 50 were \ 65 years
and 38 were [ 65 years. Patients presented with a total of 164
fractures, with 92 fractures in the younger cohort and 72 in the
older cohort. There was concomitant neurological injury in 13
patients (26 %) under 65; this figure was only 5 (13 %) of those
aged 65 or over. The most common mechanism in younger patients
was motor vehicle collision; in the older population, falls from
standing height or lower were most common. In the younger
cohort, most were managed surgically, 39 (78 %); fewer of the
older patients underwent surgery, 17 (44 %) (p = 0.001). Most
patients under 65 were able to return home after injury 33 (66 %)
whereas in those 65 years or older this was only, 12 patients
(32 %) (p = 0.001).
Discussion: The preponderance of high velocity mechanisms is a
feature that differentiates the etiology of trauma in younger patients
from that in older patients. The most frequent mechanism in older
patients suggested suggesting some underlying impairment in bone
quality; differences in mechanism may relate the to the frequency
with which neurological injury occurs, as lower velocity injuries
would, would likely be associated with less damage to neighboring
structures. The frequency of surgical management also differed
significantly. These data point to some fundamental differences in
the two patient cohorts under consideration, and should inform the
approach to management, especially in older patients.
P53
A COMPARISON OF THE EFFECT OF AGING
ON THE PRESENTATION AND MANAGEMENT
OF ACUTE FRACTURES OF THE THORACIC
SPINE
Osa Emohare, Alison Dittmer, Robert Morgan, Julie Switzer
Department of Orthopaedic Surgery, St Paul, USA
Introduction: There has been a large rise in the frequency of spinal
procedures over the last two decades. In patients over 65, this has
occurred at a frequency higher than rate of increase in the proportion of
the total US population that is over 65. In the geriatric spine, factors like
hormone levels, nutrition and degenerative change combine to produce
unique changes. The thoracic spine is pivotal role in providing axial sup-
port. This study aims to comparatively elucidate the patterns, management
and outcomes specific to acute fractures of the thoracic spine.
Methods: An Institutional Review Board approved review was con-
ducted of patients who presented between June 2010 and December
2012. Details of consecutive patients presenting to a level I trauma
center with acute fractures of the thoracic spine were collected. Patients
were stratified by age into an index group: 18-64 years, and study
group: over 65 years. The two groups were compared using parameters
which included Charlson score, management, injury characteristics and
outcome.
Results: One hundred and nine patients presented with a total of 212
fractures; the most common mechanism of injury in the younger
group were motor vehicle collisions, 20 patients (41 %); In older
patients, falls from standing height or less comprised the majority of
fractures. Most fractures in the older patient cohort were at the level
of T11 and T12, with a total of 34 fractures (39 %) at these two levels,
compare with a more even distribution across the upper thoracic and
lower thoracic levels in younger patients. In younger patients, 32
fractures (65 %) were associated with neurological injury; this figure
was 8 (13 %) in older patients (p \ 0.001). Surgery was required in
39 patients (79 %) \ 65 years and 27 patients (45 %) 65 years or
older (p \ 0.001). 30 day mortality was 1 (2 %) and 4 (7 %) in the
younger and older groups respectively.
Discussion: The impact of age on acute spine fractures is reflected in
the location, type of injury and mechanism involved. Younger
patients are frequently injured by falls from height and MVCs; these
involve significant force. In contrast, older patients, who may have a
concomitant degenerative process, were noted to sustain injuries most
frequently in the lower thoracic spine. The difference in mechanism is
also noted when the presence of associated neurological injuries is
considered. These results demonstrate significant age related differ-
ences in the nature of thoracic spine trauma.
P54
TREATMENT OF THE THORACOLUMBAR
TRAUMA BY SHORT SEGMENT PERCUTANEOUS
TRANSPEDICULAR SCREW INSTRUMENTATION.
PROSPECTIVE COMPARATIVE STUDY
WITH MINIMUM 2 YEAR FOLLOW UP
Petr Vanek, Ondrej Bradac, Renata Konopkova, Vladimir Benes
Department of Neurosurgery, Charles University, 1st Faculty of
Medicine, Central Military Hospital, Prague, Prague, Czech Republic
S740 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Introduction: In an effort to minimalize soft tissue injury percuta-
neous transpedicular systems were developed. These were originally
constructed for the treatment of degenerative conditions. The
expectation regarding better long-term outcome was not confirmed
until now. The main aim of our study is to compare clinical and
radiological outcome after stabilization by percutaneous transpedic-
ular system and stabilization from the standard open approach for
thoracolumbar spine injury.
Outcome Pain profile was assessed by the Visual analogue scale
(VAS). Two years after the surgery overall satisfaction and pain were
assessed by a simple 4-staged scale. Working ability and return to
original occupation were also monitored. Radiographic follow up was
defined by the indexes: vertebral body index (VBI), vertebral body
angle (VBA) and bisegmental Cobb angle. The accuracy of screw
placement was examined using computer tomography.
Methods: 37 consecutive patients were enrolled in the study. The
inclusion criteria were: 1. one thoracolumbar fracture classified from
A3.1-A3.3 (AO-Magerl), 2. absence of neurological deficit, 3. no other
significant injury. 18 patients were treated by short-segment minimally
invasive percutaneous pedicle screw instrumentation. The control group
was constituted from 19 patients whom were stabilized by short-segment
transpedicular construct from the standard open approach.
Results: Mean surgical time in percutaneous group was 53 ± 10 min
against 60 ± 9 min in control group (p = 0.032). In comparison of
per-operative blood loss, the percutaneous treatment group reached
better results: 56 ± 17 ml against 331 ± 149 ml in control group
(p \ 0.001). Patients in the percutaneous group scored on VAS dur-
ing the first 7 post-operative days significantly lower than those in the
control group (p \ 0.001). There was no significant difference in
values of VBI, VBA and Cobb angle between the groups during the
follow up. There was no difference in the screw placement accuracy
between the groups and no patients needed surgical revision. There
was no significant difference found at two year overall satisfaction in
both group (p = 0.402). Working ability was insignificantly better in
the percutaneous group - previous working position was achieved in
17 patients and in the control group in 12 cases (p = 0.088).
Conclusions: Percutaneous transpedicular screw technique represents
a viable option in the treatment of pre-selected thoracolumbar frac-
tures. A significant reduction in blood loss, postoperative pain and
surgical time are the main advantages associated with this minimally
invasive technique. Clinical, functional and radiological results are at
least the same as those achieved in the open technique after a two year
follow up. Short term benefits look to be apparent and long term
results have to be studied in another well designed studies.
P55
SURGICAL MANAGEMENT AND OUTCOME
OF NONTUBERCULOUS BACTERIAL
SPONDYLODISCITIS OF THE AXIAL SPINE
Renjit Krishna Kumar
Department of Orthopaedics, EDAPPALLY, COCHIN, India
Introduction: Infection of the spinal column is rare and often rec-
ognized and treated too late. Spondylodiscitis is an infection of the
intervertebral disc space, vertebral bodies, can be a serious disease
because of diagnostic delay and inadequate treatment. Presentation
can be vague and highly variable but usually includes pain and ten-
derness over the involved vertebrae and fever.
Objective: To analyze the bacteriology, pathology, complications,
management and outcome of pyogenic discitis treated in a tertiary
care referral centre by review of medical records.
Materials and Methods: Total of 42 patients were included in the
study with the range of age from 16 to 75 years and mean age being
51.61 years, male 33 and female 9. All the cases were confirmed to
have pyogenic discitis by pus culture report or histopathological
examination. Mean follow-up period was 9.6 months, with a range
from 6 to 26 months. Five patients (11.9 %) presented with neuro-
logical deficits and 13 patients (30.95 %) had other co-morbidities
like diabetes mellitus, renal failure, chronic obstructive pulmonary
disease (COPD), heart diseases, and malignancies. Five cases
(11.9 %) had previous operation of the involved level and three
(7.14 %) cases had history of vertebral fractures. Three patients
(7.14 %) were operated for gynaecological problems and four cases
(9.52 %) had history of urological surgery.
Results: Lumbar spine was the most frequent site of pyogenic discitis
(29 cases, 69.04 %) followed by dorsal and cervical spine respec-
tively. The most common bacteria isolated was Staphylococcus
aureus in 19 cases (45.23 %) followed by E coli (4 cases, 9.52 %) and
Klebsiella pneumoniae (3 cases, 7.14 % %). Debridement and pos-
terior lumbar interbody fusion (PLIF) was done in 17 cases
(40.47 %), transforaminal lumbar interbody fusion (TLIF) was done
in 8 cases (19.04 %), anterior cervical discectomy and fusion (ACDF)
was done in 7 cases (16.66 %) and anterior lumbar interbody fusion
(ALIF) was done in 5 cases (11.9 %). Five patients were treated
conservatively.
Conclusion: The pyogenic discitis should be suspected for people
having pain and local tenderness in spinal region with rise of
inflammatory parameters in blood investigations. Although the most
common bacteria were S aureus but there were still greater number of
patients infected by the other types of bacteria. Therefore antibiotics
therapy should be started only after obtaining laboratory evidence of
the involved bacteria and the drug sensitivity.
Key words: pyogenic infection, spondylodiscitis, spinal instrumen-
tation, antibiotics
P56
THIRTY DAY MORTALITY RATE
IN THE SURGICAL TREATMENT
OF METASTATIC SPINAL CORD COMPRESSION
Sakthivel Rajan Rajaram Manoharan, Nasir Quraishi,
Deepshri Sureshkumar, Hussein Mehdian, Bronek Boszczyk
Centre for Spinal Studies and Surgery, Queens Medical Centre,
Nottingham, UK
Objectives: Emergency surgical treatment in MSCC has been shown
to improve function and neurological outcome. Inpatient patient
mortality is of course devastating. Our aim was to review our 30 day
inpatient mortality rate in patients undergoing surgery for MSCC,
with the intention of analysing the causes and to further scrutinise our
patient selection for surgical intervention.
Methods: We reviewed all patients treated surgically from our
comprehensive database. All data was collected retrospectively from
October 2004-October 2009, then prospectively from October
2009-October 2011 (7 years). We reviewed all patient records held on
the database, including patient demographics, primary tumour, neu-
rological outcome (Frankel grade) and survival.
Results: During the 7 year study period, in total 302 patients who
underwent emergency surgery for MSCC in our institution, 243 were
included in whom complete information was available. There were 29
patients who died within 30 days of surgery (12 %; mean age
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S741
123
65.2 years, 17 M, 12 F) with an average survival of 19.6 days (from
index operation).
The reasons for the mortality were respiratory complications (n = 12)
sepsis (n = 6), rapid disease progression (n = 3), stroke (n = 1),
gastrointestinal bleed (n = 1) and cerebral metastases causing intra-
cranial bleed (n = 1). The cause of death was unknown in 5 patients.
When comparisons were made with patients who survived at least
6 months(n = 80), then were significantly lower revised Tokuhashi
score 7.2 vs 9.7; (p \ 0.05), older patient group 65.4 vs 59.5
yrs(p \ 0.03) and more lung tumour primaries in the 30 day mortality
group(n = 9) vs (n = 3) in the other group.
Conclusions: Our 30 day mortality rate following emergency surgery
for MSCC was 12 % and most of the patients died within 3 weeks of
surgery. Older patients with lower revised Tokuhashi and lung
primaries were the poorest survivors. This study may help to assist
with better patient selection for surgical intervention in these patients.
P57
POSTOPERATIVE URINARY TRACT INFECTION
AND SURGICAL SITE INFECTION
IN INSTRUMENTED SPINAL SURGERY: IS THERE
A LINK?
Susana Nunez-Pereira, Rodrıguez-Pardo Dolors, Pellise Ferran,
Carles Pigrau, Joan Bago, Enric Caceres
Spine Surgery St Franziskus Hospital, Cologne, Germany
Introduction: Urinary tract infection (UTI) and surgical site infection
(SSI) are the most common minor and major complications following
posterior spinal fusion and instrumentation (PSFI). Quinolones (i.e.
ciprofloxacin), often used for treatment of UTI are, in combination
with other agents, one of the treatments of choice for implant asso-
ciated infections, especially against Staphylococcus aureus resistent
to methicillin and against gram negative bacteria.
Objectives: The aims of this study were to analyze a potential rela-
tionship between UTI and SSI, and to evaluate the possible effects of
using quinolones for treatment of UTI in further development of
antibiotic resistances at SSI.
Materials and methods: Retrospective study of prospectively col-
lected data from consecutive patients who underwent PSFI in a single
centre. Demographic, clinical and microbiological data were col-
lected. UTI occurring in the first 4 weeks, SSI (superficial and deep)
occurring in the first 12 weeks after PSFI and antibiotic treatments
were recorded. Statistical analyses used the Chi square test to com-
pare proportions and logistic regression to study risk factors for SSI.
Results: 446 patients were included: 58.6 % women, mean age 50.3 (SD
19.5), 40.8 % ASA Score [ 2, and 49.8 % fusion of more than 3 seg-
ments. Eighty-nine patients had confirmed UTI, 54 had SSI, and 22
presented both infections. In only 9 of these 22 cases were the two
infections caused by the same microorganism. Multivariate analysis
identified fusion of more than three segments (OR = 3.0, 95 % CI 1.5-
6.0; p = 0.003) and UTI (OR = 2.9, 95 % CI 1.4-5.7; p = 0.002) as
independent risk factors for SSI. Patients receiving ciprofloxacin for UTI
showed higher resistance rates to quinolones at the surgical site cultures
(46.13 %) compared to patients who did not take ciprofloxacin before SSI
(21.9 %). The difference did not reach statistical significance (p = 0.1),
but the power of the analysis was very low due to the small sample size.
Discussion: UTI is a significant risk factor for SSI after PSFI. Further
efforts to reduce the incidence of UTI and to provide adequate
empirical antibiotic therapy that avoids quinolones may help to
reduce the incidence of SSI and potential microbiological resistances.
P58
RADIOLOGIC FINDING OF FAILED
PERCUTANEOUS VERTEBROPLASTY
Wei-Chiang Liu, Sang-Ho Lee, Won Gyu Choi, Dong-Yeob Lee,
Sung Suk Paeng, Amy Kwon
Radiology, Seoul, Korea (ROK/South Korea)
Objective: Vertebroplasty is extensively performed worldwide for the
treatment of thoracic and lumbar osteoporotic compression fractures.
Although percutaneous vertebroplasty is considered a minimally
invasive procedure, it may result in several complications. The pur-
pose of this study was to evaluate the etiology of failed percutaneous
vertebroplasty.
Materials and Methods: We retrospectively reviewed the clinical
data and imaging findings of 23 patients (4 men and 19 women) who
were treated with corpectomy after percutaneous vertebroplasty for
compression fracture from 2007 through 2012. The average age of the
patients at the time of admission was 71.8 years (range, 61-86 years).
To diagnose the etiology of failed percutaneous vertebroplasty, we
evaluated the preoperative magnetic resonance (MR) images findings
such as fracture type, avascular necrosis, fluid collection in the
fracture segment, kyphosis, interspinous ligament injury, adjacent
interbody fusion, compression fracture with infection and poor-
quality of the image.
Results: The average length of days from percutaneous vertebroplasty
to corpectomy was 140.3 days. Among the 23 patients with failed
percutaneous vertebroplasty, 11 (47.8 %) had confirmed compression
fracture and 12 (52.2 %) had confirmed bursting fracture. Eight of the
23 patients (34.8 %) had missed diagnosis of interspinous injury, 5
patients (21.7 %) had poor-quality MR image for the evaluation of
interspinous ligament injury, and 3 patients (13.0 %) had no fat-sat-
urated T2-weighted images for the evaluation of interspinous
ligament injury. Avascular necrosis, kyphosis, compression fracture
with infection, and adjacent interbody fusion were observed in 10
(43.5 %), 3 (13.0 %), 1 (4.3 %), and 5 (21.7 %) of the 23 patients,
respectively.
Conclusion: We reported the MR findings of failed percutaneous
vertebroplasty. Evaluation of the interspinous ligament using high-
quality MR images is important before performing percutaneous
vertebroplasty for the treatment of osteoporotic compression
fractures.
P59
RECONSIDERATION OF THE TREATMENT
STRATEGY FOR THORACOLUMBAR
FRACTURES CAUSED BY HIGH ENERGY FORCE
Yasunori Sorimachi, Kanako Tsuihiji, Takashi Nakajima,
Eiji Takasawa, Ryoichi Kobayashi, Yoichi Iizuka, Haku Iizuka,
Kenji Takagishi
Orthopaedic and Spine Surgery, Japanese Red Cross Maebashi
Hospital, Gunma, Japan
Introduction: Thoracolumbar spine injury is usually caused by high
energy force, so it often occurs as a component of multiple trauma.
Therefore, early mobilization is required to prevent complications of
bed rest such as venous thromboembolism and atelectasis, to facilitate
nursing care. This study investigated clinical results of thoracolumbar
S742 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
fractures in recent years, and evaluated the previous treatment strat-
egy for these fractures.
Methods: 53 consecutive patients with thoracolumbar fractures (T11-
L2) caused by high energy trauma treated in our hospital between
October 2006 and September 2011 were reviewed. Age, AO classi-
fication, ASIA impairment scale, load sharing classification (LSC)
and thoracolumbar injury classification and severity score (TLICS),
local kyphosis angle (LKA), immobility period and residual back pain
were investigated. For the statistical analysis, the subjects were
divided into three groups: operative group (O); conservative group
with TLICS 3 or less (C1); conservative group with TLICS 4 or more
(C2).
Results: In 14 cases of Group O (the average age was 37.6 years, AO
A3: 1 case, B1: 5 cases, B2: 8 cases, LSC 6.4, TLICS 6.9), 22 cases of
Group C1 (50.0 years, A1: 3, A2: 1, A3: 18, LSC 4.0, TLICS 1.8) and
17 cases of Group C2 (44.0 years, B1: 9, B2: 8, LSC 4.3, TLICS 5.6),
the most common level injured was L1. All 5 cases with neurological
deficit (ASIA A: 1, C: 3, D: 1) were recognized in Group O. The LKA
at the injury was 15.8� in Group O, 10.3� in Group C1 and 13.1� in
Group C2. There was no difference between conservative groups
(Cs). The LKA at the final follow-up was 11.7� in Group O, 14.1� in
Group C1 and 22.2� in Group C2. The LKA in Group C2 significantly
increased between Group Cs. The immobility period was 7.6 days in
Group O, 26.1 days in Group C1 and 30.9 days in Group C2. There
was no difference between Group Cs. The residual back pain was
revealed in 3 cases (21.4 %) of Group O, 9 cases (40.9 %) of Group
C1 and 10 cases (58.8 %) of Group C2. Prevalence rate was signifi-
cantly higher in Group C2 than in Group O.
Conclusion: Previously, we adopted conservative treatment for
patients without instability and paralysis, and determined the duration of
bed rest for 2 to 8 weeks. However, this study showed that the severity
of the fracture did not reflect conventional determination of bed rest
period. Moreover, conservative therapy with prolonged immobility, in
cases of TLICS 4 or more, did not prevent kyphotic deformity.
BASIC SCIENCE
P60
A SINGLE NUCLEOTIDE POLYMORPHISM
IN THE HUMAN BMP-2 GENE (109T [ G)
AFFECTS SMAD SIGNALING PATHWAY
AND THE PREDISPOSITION TO OSSIFICATION
OF POSTERIOR LONGITUDINAL LIGAMENT
OF SPINE
Baorong He, Dingjun Hao, Liang Yan
Hong Hui Hospital, Xi’an Jiaotong University College of Medicine,
Xi’an, China
Objective: To investigate whether BMP-2 is a candidate gene to
modify the susceptibility of OPLL and the mechanism of ossification
in signal transduction.
Methods: A total of 420 OPLL patients and 506 age- and sex-mat-
ched controls were studied. The complete coding sequence of the human
BMP-2 gene were analysed through PCR and direct sequencing, all the
SNPs were detected and genotype. The BMP-2 expression vectors
containing positive polymorphisms were constructed and transfected to
the C3H10T1/2 cell. The expression of BMP-2 and Smad signal path-
way in positive cell clones were detected by western blotting. The ALP
activity was detected by quantitative detection kits.
Results: The frequencies for the 109T [ G and 570A [ T poly-
morphisms were difference between the case and control group. The
‘‘TG’ genotype in 109T [ G polymorphism is associated with the
occurrence of OPLL. The ‘‘AT’ genotype in 570A [ T polymorphism
is associated with the occurrence of OPLL. The expression of Smad4
protein transfected by wild-type or mutant expression vectors were
significantly higher than control groups (P \ 0.05), the expression of
Smad4 protein transfected by pcDNA3.1-BMP2 (109G) and
pcDNA3.1-BMP2 (109G, 570T) were significantly higher than the
other experimental groups(P \ 0.05). The ALP activity increase has
been detected in pcDNA3.1-BMP2 (109G) and pcDNA3.1-BMP2
(109G, 570T) transfected cells to 4 weeks after stably transfection.
The activity ALP results were (30.56 ± 0.46) nmol/minute/mg pro-
tein and (29.62 ± 0.68) nmol/minute/mg protein, respectively. There
was a statistical difference compared with the other experimental
groups (P \ 0.05).
Conclusions: The BMP-2 is the predisposing gene of OPLL. The
‘‘TG’ genotype in the 109T [ G and the ‘‘AT’ genotype in the
570A [ T polymorphisms are associated with the occurrence of
OPLL. In the intracellular signalling transduction, the 109T [ G
polymorphism in exon-2 of BMP-2 gene is positively associated with
the level of Smad4 protein expression and the activity of ALP. Smad
mediated signalling pathway plays an important role during the
pathological process of OPLL induced by SNPs of BMP-2 gene.
P61
POSTEROLATERAL SPINAL FUSION USING
ESCHERICHIA COLI-DERIVED RHBMP-2
WITH HYDROXYAPATITE GRANULE
Chang-Bae Kong, Choon-Ki Lee, Jin Sup Yeom, Jae-Hyup Lee,
Hyoungmin Kim, Bong-Soon Change
Department of Orthopaedic Surgery, Seoul, Korea (ROK/South Korea)
Introduction: Mini-pig posterolateral spinal fusion model was used
to analyze the osteoinductivity of rhBMP-2 using HA granules as a
carrier, which can be potentially applicable in a clinical setting for the
treatment of human spinal diseases.
Methods: Thirty-one adult male mini-pigs underwent a single level
laminectomy followed by bilateral intertransverse process arthrodesis.
Those were randomized into control (HA 3 g), low dose (HA
3 g + rhBMP-2.1 mg) and high dose (HA 3 g + rhBMP-2.3 mg)
groups. Each animal was euthanized at 3 months after surgery. Fusion
status and degree of bony mass formation were evaluated by radio-
logic and histologic examinations.
Results: Three mini-pigs were dead and exlcluded for analysis. The
fusion rate were 37.5 % for control group, 71.4 % for low dose group and
84.6 % for igh dosed group (p = 0.031). The volume of fusion mass
determined by 3D CT and micro CT showed largest in high dose group
(p\ 0.001). The HA volume was not different but the new bone volumes
showed significant differnece: 9590 ± 1105 mm3 for control group,
14898 ± 2540 mm3 for low dose group and 23831 ± 8015 mm3 for high
dose group (P\ 0.001). The bone volume fractions (bone volume/tissue
volume), trabecular thicknesses, trabecular numbers and trabecular
separations were also analyzed and the differences between groups were
not statistically significant.
Histologic analysis showed that solid bridging bone was seen in the
19 mini-pigs in which fusion was achieved, as measured by palpation
and radiographs. Normal appearing mature osteoblast-lined trabecular
bone was present between the proximal and distal transverse pro-
cesses. There was no evidence of inflammatory cells or other reaction
to the carrier.
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S743
123
Seven animals developed wound complications. One is from con-
trol group, 2 from low dose group and 4 from high dose group.
There was no statistical difference between groups according to the
infection development (P = 0.623). When further stratified by deep
or superficial wound infections, 3 subjects from high dose group
were classified as superficial ones and they achieved solid bony
union.
Conclusion: The E-coli-derived rhBMP-2 in usage with carrier of HA
granule induced successful posterolateral fusion in mini-pigs.
P62
CONSTRAINED INTERVERTEBRAL DISC ORGAN
CULTURE FOR SIMULATION OF CELL THERAPY
APPROACHES
Cornelia Neidlinger-Wilke, Antje Boldt, Graciosa P.Q. Teixeira,
Christopher Jahn, Jurgen A. Mollenhauer, Hans-Joachim Wilke,
Anita Ignatius, Mario Barbosa, Raquel Goncalves
Institute of Orthopaedic Research and Biomechanics, Ulm, Germany
Introduction: Purpose of the study was to establish a bovine disc
organ culture model with simulation of pro-inflammatory conditions.
This model system was characterized with regard to its suitability for
testing the fate of injected cells under simulation of a degenerative
disc environment.
Materials and methods: Bovine caudal disc punches (each 5-6 discs
from 12 tails) cultured at constrained conditions were exposed to
needle-puncture treatment and/or application of pro-inflammatory
molecules (LPS, IL1b and TNFa) or maintained as untreated controls.
At day 2 after culture initiation, part of the discs was injected with
fluorescence labeled cells (PKH-67/26) within an albumin-based
hydrogel. The induction of a pro-inflammatory response was evalu-
ated by quantification of prostaglandin (PGE2) production in the
conditioned media and by gene expression analysis of pro-inflam-
matory cytokines and MMPs from isolated disc cells. The metabolic
profile of cultured discs was traced by glucose consumption. Discs
with injected cells were analyzed after 1, 2 and 4 weeks of incubation
by histomorphology, immuno-histochemistry and by determination of
glycosaminoglycan content.
Results: Treatment of needle-punctured disc organ cultures with LPS
or IL1b increased PGE2 12-fold in conditioned media of the disc
explants. Glucose consumption levels indicate that cultured discs
were not starving (above 0.2 g/l) and the LPS-treated samples showed
higher glucose consumption than controls. Annulus and Nucleus cells
treated with LPS or IL1b showed a strong up-regulation of MMP3,
MMP13, IL-6, and IL8 expression. GAG contents decreased
(62.4 ± 9 %) within 2 weeks in culture. Though only small volumes
of cell-seeded hydrogels could be injected into the discs, fluorescent
cells were detected at each sampling time point. Disc matrix around
cells close to the injection site showed a more intense Alcian blue
staining suggesting a locally increased GAG deposition.
Discussion: Through simulation of degenerative and/or inflammatory
environment conditions under controlled organ culture conditions this
model is suitable with regard to in vitro testing of regenerative or anti-
inflammatory treatment strategies of disc degeneration. The moni-
toring of injected fluorescence-labelled cells allows continuous
characterization of cell reactions in this organ culture environment.
Supported by HEALTH-F2-2008-201626, CP-IP 213904 and Deut-
sche Wirbelsaulenstiftung.
No conflict of interest to declare.
P63
END PLATE TRANSITION FROM CARTILAGE
TO BONE IN THE AGEING MURINE
INTERVERTEBRAL DISC: ROLE FOR BMP2
Esmeralda Blaney Davidson, Elly Vitters, Wim van den Berg,
Peter van der Kraan
Rheumatology Research & Advanced Therapeutics, Nijmegen,
Netherlands
Purpose: Degeneration of the intervertebral disc (IVD) is considered a
source of back pain and affects 80 % of the ageing population. Mech-
anisms underlying age-related IVD degeneration remain unclear. We
studied age-related changes in IVD gene expression to find clues
explaining age-related IVD degeneration. We show that with age the
end plate underwent terminal differentiation followed by bone forma-
tion accompanied by high osteocalcin mRNA expression and intense
BMP2 staining.
Methods: We isolated lumbar spines of C57Bl/6 mice aged
2-20 months for RNA isolation or histology. Spines were decalcified
with EDTA, IVD were isolated, followed by RNA isolation and RT-
PCR. Q-PCR was performed for aggrecan, collagen type I, collagen
type II, collagen type X and osteocalcin and Id1. Values were cor-
rected for GAPDH and compared to 4 months of age. For histology,
paraffin sections were stained with Safranin O and Fast Green.
Immunohistochemistry was performed for BMP2.
Results: In the IVD aggrecan mRNA decreased 1.9-fold by
20 months. Collagen type II increased 3.7 fold by 12 months of age
and remained stable thereafter. Collagen type I also increased up to
4.5 fold by 12 months of age and slightly reduced again to 3.3 fold
increase. The most striking change was increased osteocalcin of 3.2,
5.4 and 6.1 fold, by 8, 12 and 20 months respectively. This indicated
bone formation with an onset even before 8 months of age.
We investigated the potential cause of the osteocalcin increase his-
tologically. Already at 6 months, end plate chondrocytes underwent
hypertrophic differentiation and were eventually replaced by bone
resulting in a bone layer covering the growth plate. As BMP2 is a
major inducer of bone we investigated its presence and found
increased staining with age especially intense in the terminally dif-
ferentiating end plate chondrocytes. These increased BMP2 levels
resulted in downstream alterations as well as we found Id1 mRNA
levels increased 1.4 fold by 8 months and 2.8 fold by 12 months and
was stable thereafter.
Conclusions: Our data show that with age, end plate chondrocytes
undergo terminal differentiation and are eventually replaced by bone.
This is accompanied by an intense increase in BMP2 staining in the
hypertrophic cells and a sustained increase in osteocalcin levels and
increased Id1 expression. Our data strongly suggesting a role for
BMP2 in bone formation in the IVD end plate. This phenomenon will
contribute to age-related degeneration of the IVD.
P64
MAPK INHIBITION SELECTIVELY MITIGATES
INFLAMMATORY MEDIATORS PRODUCTION
IN DISC CELLS CO-CULTURED WITH ACTIVATED
MACROPHAGE-LIKE THP-1 CELLS
Joo Han Kim
Department of Neurosurgery, Seoul, Korea (ROK/South Korea)
S744 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Recent data have suggested that macrophages are involved in the
pathogenesis of intervertebral disc (IVD) degeneration and enhance
the secretion of inflammatory mediators in co-cultured disc cells. The
purpose of these studies is to determine the role of mitogen-activated
protein kinase (MAPK) signaling in the interactions between mac-
rophage and IVD cells.
Human annulus fibrosus (AF) cells and nucleus pulposus (NP) cells
were co-cultured with phorbol myristate acetate-stimulated macro-
phage-like THP-1 cells with and without SB202190 (p38 MAPK
inhibitor), SP600125 (JNK MAPK inhibitor), and PD98059 (ERK
MAPK inhibitor). Conditioned media from co-cultured cells were
assayed for tumor necrosis factor (TNF)-a, interleukin (IL)-1b, -6, -8,
and nitric oxide (NO). Human AF cells and NP cells were also cul-
tured with proinflammatory cytokine to find the activation of NF-kb
and MAPKs.
IL-6, IL-8, and NO were secreted in greater quantities by cells
maintained in co-culture compared to macrophages (M) cultured
alone. TNF-a and IL-6 production in NP co-culturing with M were
significantly lower than AF co-culturing with M. SB202190 dose-
dependently suppressed IL-6 secretion in AF-M and NP-M co-culture
while did not significantly suppressed TNF-alpha, IL-1beta, and IL-8.
10 uM SP600125 and PD600125 suppressed the TNF-alpha, IL-8 in
the AF-M and NP-M co-culture. 1 ng/mL IL-1b and 10 ng/mL TNF-
a, which are major proinflammatory cytokines of macrophage, acti-
vated NF-kB and MAPKs (p38, JNK1/2, and ERK 1/2) protein. in the
AF and NP cells. IL-6 production from macrophage-exposed NP was
significantly strikingly blunted by p38 and ERK MAPK inhibition
while IL-8 production was significantly blunted to p38 MAPK
inhibition,
Symptomatic IVD degeneration can result in macrophage infiltration
at the AF and NP, and this can cause enhanced inflammatory medi-
ators from AF and NP. The MAPK pathway signals are selectively
responsible for cytokines secretion in disc cells with macrophage-like
cells and p38 MAPK are more responsible for IL-6 and IL-8 pro-
duction in previous macrophage-exposed disc cells than JNK and
ERK MAPK pathway, suggesting that selective blockade of these
signals may serve as a therapeutic approach to symptomatic disc
degeneration.
P65
THE EFFECT OF BIPHASIC ELECTRICAL
CURRENT STIMULATION ON IL-1B STIMULATED
ANNULUS FIBROSUS CELLS USING IN VITRO
MICRO-CURRENT GENERATING CHAMBER
SYSTEM
Joo Han Kim, Jae Hee Shin
Department of Neurosurgery, Seoul, Korea (ROK/South Korea)
Symptomatic disc degeneration is an important cause of chronic
intractable lumbar pain, which is associated with macrophage-
mediated inflammation in the AF. Although some studies suggest
that in vitro electrical stimulation can up-regulate collagen pro-
duction and diminished inflammatory mediators in osteoarthritis,
their effects on human AF inflammation remain unknown. To
identify the effect of a biphasic electrical current on ECM regu-
lated enzymes and inflammatory mediators in IL-1b stimulated AF,
we evaluated the influence of biphasic electrical field stimulation
on the expression of inflammatory mediators and ECM regulated
enzymes in IL-1b stimulated annulus fibrosus (AF) using in vitro
culture system.
Human AF (hAF) cells were cultured with micro-current generating
chamber (MCG) system (0, 50, 250, 500 mV/mm) in presence of
1 ng/mL IL-1b. Conditioned media from cells were assayed for
MMP-1,-3, TIMP-1, -2, IL-6, -8, NO, VEGF, and IGF-1 by ELISAs.
Gene expression in AF pellets was assay for COX-2 and COL1A2 by
real time reverse transcriptase polymerase chain reaction (RT-PCR).
IL-1b stimulated hAF produced significantly higher levels of MMP-1,
-3, IL-6, IL-8, NO, and VEGF, and lower levels of TIMP-1 and -2. IL-
6, NO, MMP-1, TIMP-1, VEGF, and IGF-1 were time-dependently
increased through 72 h under 250 mV/mm. MMP-1, TIMP-1, IL-6,
and VEGF were not changed at 0, 50, and 250 mV/mm while
decreased at 500 mV/mm compared to control (MMP-1,
17.2 ± 4.7 ng/mL, p \ 0.05;TIMP-1, 12.4 ± 3.3 ng/mL, p \ 0.02;
IL-6, 2.5 ± 0.9 ng/mL, p \ 0.05 and VEGF, 0.1 ± 0.04, ng/mL,
p \ 0.03). MMP-3, IL-8, and IGF-1 were not significantly influenced
according to intensity of electrical field stimulation. NO were not
changed between 0, 50, 250 mV/mm while strikingly increased at
500 mV/mm (p \ 0.0001).
In present study, we confirmed that electrical field stimulation suc-
cessfully suppressed MMP-1, IL-6, and VEGF on 500 mV/mm while
did not influence to MMP-3, IL-8 and IGF-1. Furthermore, electrical
field stimulation significantly suppressed the TIMP-1 on 500 m/mm,
suggesting the selective efficacy of electrical field stimulation to blunt
symptomatic cervical disc degeneration.
P66
LONG-TERM IN VIVO KINEMATICS
OF THE LUMBAR INTERVERTEBRAL DISC
TRANSPLANTATION IN A GOAT MODEL
Keith Luk, Yong-can Huang, Jun Xiao, William Lu, Victor Leung
Orthopaedics and Traumatology, Pokfulam, Hong Kong
Purpose: Intervertebral disc (IVD) allograft transplantation in the
human cervical spine is able to restore segmental kinematics.
Extending this technique to the lumbar spine remains a challenge
because of the difference in anatomy and loading mechanics. This
study evaluated the long-term in vivo kinematics of the spinal seg-
ment following IVD transplantation in the goat lumbar spine model.
Methods: Twelve male goats between 6 and 9 months weighing
between 17.5 and 25 kg were used in this study. Two goats served as
allografts donor, 5 as allograft recipients where a graft was trans-
planted into L4-5, and the remaining 5 as untreated controls. Post-
operation lateral radiograph of the lumbar spine in the neutral, flexion
and extension positions were taken at 1, 3, 6, 9 and 12 months. Disc
height (DH) of the allograft and the adjacent levels were measured
and the range of motion (ROM) of the transplanted segment, the
adjacent levels, and the global lumbar spine were measured using the
Cobb’s method.
Results: All the disc allografts were well seated without subluxation
or dislocation. Immediately post-operation, the average DH of the
allograft was 3.04 ± 0.57 mm. This decreased slightly to
2.51 ± 0.54 mm after 1 m which is not significant statistically. The
DH further decreased to 1.91 ± 0.28 mm at 3 months post-op but
stabilized thereafter (One-way ANOVA, P [ 0.05). The DH of the
adjacent levels exhibited no significant change throughout the
observation period.
At 1 m post-operation, the average ROM of the allograft segments
was 6.4� ± 1.8� while that of the cranial and caudal adjacent seg-
ments were 6.7� ± 3.4� and 6.1� ± 2.4� respectively. At the final
follow-up, the respective ROMs were 6.7� ± 4.2�, 5.2� ± 2.2� and
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S745
123
10.1� ± 4.4�. When compared with the average ROM of the two
adjacent segments considered together, the mean ROM of the trans-
planted segment it was not statistically significant (Paired-Samples T
test, P [ 0.05). It was also comparable to that of the L4-5 disc in the
untreated controls (5.5� ± 2.5�). The global ROM of the lumbar spine
after disc transplantation was well preserved when compared to that
of the untreated goats (P [ 0.05).
Conclusion: Lumbar intervertebral disc transplantation could restore
the global and segmental mobility after 12 months despite a mean
reduction of the allograft height at the initial three months. A study on
the center of rotation at the grafted segment is underway.
P67
DNA DAMAGE IN INTERVERTEBRAL DISC
CELLS ACCELERATES DISC DEGENERATION
THROUGH MATRIX LOSS IN A MOUSE MODEL
OF HUMAN PROGERIA
Luigi Aurelio Nasto, Enrico Pola, Debora Colangelo,
Andria Robinson, Gwendolyn Sowa, Peter Roughley,
Laura Niedernhofer, James Kang, Nam Vo
Division of Spine Surgery, Department of Orthopaedic Surgery,
Catholic University of Rome, Rome, Italy
Introduction: Deficiency in DNA repair induces rapid biological
ageing which invariably associates with disc matrix proteoglycan
loss. Thus we hypothesize that DNA damage, when not repaired,
can promote disc aging and matrix loss. To test our hypothesis, we
challenged wild-type mice and their DNA repair deficient Ercc1-/Dlittermates with the genotoxic cross-linking agent mechlorethamine
(MEC) or chronic ionizing radiation (IR) to induce DNA damage.
Methods: Ercc1-/D mice (n = 6) and their wild-type littermates were
chronically exposed to genotoxic stress beginning at 8 weeks by
subcutaneous administration of a subtoxic dose of MEC (8 lg/kg
once per week for 6 weeks) or & 10 % radiotherapeutic dose of
ionizing radiation (0.5 Gy 1 9 per week for 10 weeks). Safranin O
histological staining for proteoglycan and Masson’s Trichrome for
collagen were performed. Disc aggrecan, ADAMTS4, and ADAMTS-
generated G1 aggrecan fragments terminating in NITEGE-373 were
analyzed by immunohistochemistry (IHC). Proteoglycan synthesis
was measured by 35S-sulfate incorporation using disc organ cultures.
Results: Histological staining revealed substantial reduction in matrix
collagen, proteoglycan and endplate cellularity in the discs of MEC-
exposed and irradiated mice. IHC analysis showed decreased aggre-
can content and increased levels of ADAMTS4 and NITEGE-373
containing aggrecan proteolytic fragments. Disc PG synthesis was
reduced 2-3 folds in MEC-treated mice. The overall effect of the
treatment on disc matrix and endplate cartilage was more severe in
Ercc1-/D mice than in wild-type mice.
Conclusion: MEC and IR treatment resulted in loss of disc matrix
proteoglycan and collagen in adult wild-type and Ercc1-/D mice
through a combination of decreased matrix synthesis and increased
breakdown. The finding that loss of matrix proteoglycan was greater
in the DNA repair deficient mice strongly supports the conclusion that
DNA damage can drive disc degeneration. These results implicate
DNA damage as a contributor to disc aging and degeneration. Thus
Ercc1-/D mice, a novel and rapid murine model of age-related disc
degeneration, are useful for exploring the molecular mechanisms by
which DNA damage promotes age-related disc matrix loss and
degeneration. The results of this work may have important implica-
tions for long-term cancer survivors patients treated with genotoxic
agents.
P68
FRICTION MEASUREMENT OF A METAL-ON-
POLYETHYLENE TOTAL DISC REPLACEMENT
Philip Hyde, John Fisher, Richard Hall
Mechanical Engineering, Leeds, UK
Introduction: Compared to total hip replacements (THR), articulat-
ing total disc replacements (TDR) typically utilise bearing materials
that are reversed (i.e. a polymer head on a metallic cup). This has
resulted in unexpected wear phenomena such as edge-loading [1] and
debris re-attachment [2] that have highlighted the differences between
TDR and THR bio-tribology. The replacement of a natural visco-
elastic intervertebral disc with an articulating TDR is a fundamental
change in design rationale when compared to hip and knee replace-
ment theory. Further, pull-out torque was once a concern in THR and
may be of issue for TDR.
Aim: To investigate the effect of loading and serum concentration on
the frictional behaviour of a semi-constrained TDR.
Method: TDR components (n = 3) were mounted in a pendulum
friction simulator in a bath of lubricant of bovine serum diluted to
25 % (v/v). Constant loadings were applied in a pseudo-random order
to avoid bias caused by the preceding test over a range from 500 to
2750 N and FE inputs of ± 4.58 were used. Serum concentration was
then tested between 0 % (full water) to 100 % serum at a constant
1500 N load.
Results: Frictional torque varied from 0.6 Nm (500 N load) to 2.4 Nm
(2750 N load), giving friction factors of 0.082 to 0.060. The constant
load friction factors were proportional to the load raised to index
power -0.28. No significant difference was observed between friction
measurements using serum concentrations from 0-100 % (p = 0.9,
ANOVA). Increasing the serum concentration increased the friction
slightly, but this trend was also not significant (Pearson’s linear
correlation, p = 0.17).
Discussion: The friction factors were equivalent to those reported for
MoP and CoP hips [3].Typical torque developed was * 1.5 Nm
(1500 N axial load). This is below the torque developed in the natural
IVD per 18 flexion (1.7 Nm/8 [4]) and so pull-out concerns are
minimal. The decrease in friction with increasing load (L-^0.28) is
typical of dry friction in polymers and may indicate poor lubrication.
References:
1. Hyde et al., Journal of ASTM International, 2011. 9(2): p. 51-65.
2. Vicars et al., European Spine Journal, 2010. 19(8): p. 2010,
1356-1362.
3. Brockett et al., J Biomed Mater Res B Appl Biomater, 2007. 81(2):
p. 508-15.
4. Panjabi et al., Spine, 1984. 9(7): p. 707-713.
P69
DYNAMIC STATE AND LOCALIZATION
OF MICROGLIA IN INJURED SPINAL CORD
BY THE PERIPHERAL BENZODIAZEPINE
RECEPTOR LIGAND PK11195
Shuji Watanabe, Kenzo Uchida, Hideaki Nakajima, Takayuki Hirai,
Hisatoshi Baba
Department of Orthopaedic Surgery, University of Fukui, Fukui,
Japan
S746 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Introduction: In acute spinal cord injury (SCI), the primary
mechanical injury is followed by post-traumatic inflammation and
various inflammatory cells are migrated around the lesion site. In
these cells, resident microglia is commonly known that mainly
associated with repair of spinal cord, but there is no precise method of
quantification activated microglia in injured spinal cord. The present
study was aimed to investigate the benefits of peripheral benzodiaz-
epine receptor (PBR), known as a marker of glial activation in central
nervous system, and autoradiography using PK11195, known as
specific antagonist of PBR, for evaluation of microglial activation in
SCI mice.
Methods: We used C57BL/6 mice (8-12 weeks old), and we also
made chimeric mice transplanted EGFP + bone marrow cells from
CAG-EGFP transgenic mouse in order to distinguish from hematog-
enous macrophages. Mice were subjected to T9-T10 SCI by
contusion. In 7, 14, 28 days after injury, mice spinal cord was
resected and the part of 2 mm caudal side was cut into serial 20-lm
thick axial frozen section. For immunofluorescence, the sections were
incubated with CD11b, Iba-1, PBR antibodies. For autoradiography,
the sections were incubated in PBS containing 1nM [3H](R)-
PK11195 and developed after a few weeks. Cellular localization and
quantification analysis of PK11195 was evaluated and compared to
results of immunofluorescence.
Results: In immunofluorescence, PBR positive cells are located in
gray matter and almost cells were merged with CD11b, Iba-1 positive
cells. The cell counting of PBR was performed on a semiquantitative
level, so PBR positive cells increased from 4 days up to more than
14 days post injury and a lot of PBR positive cells were not merged
with GFP + cells, hematogenous cells. In autoradiography, accumu-
lation of PK11195 was identified in gray matter and were up from
4 days to 7 days post injury. In chronic phase, accumulation
decreased.
Conclusion: Our results suggest that PBR is mainly located in resi-
dent microglia and hematogenous macrophage in injured spinal cord.
From the results of double staining with GFP positive cells. PBR is
dominantly located in resident microglia than hematogenous macro-
phage. Therefore, autoradiography of PK11195 has potential to be
able to evaluate the activation of microglia.
P70
LUMBAR FLEXOR–EXTENSOR RATIO DOES
NOT CHANGE WITH AGE DESPITE
A REDUCTION IN MULTIFIDUS VOLUME
Stephanie Valentin, James Elliott, Theresia Licka
Movement Science Group Vienna, Vienna, Austria
Introduction: Trunk musculature is an important contributor to spinal
stability. In a healthy population, ageing leads to generalised muscle
volume loss. Whilst the benefits of synergistic muscle activity for a
supported spine are well reported, age-related changes of relative
muscle volume are less well-documented. Therefore, the aim of this
preliminary study was to identify trunk muscle volume and ratio of
flexors to extensors in a young and mature group of healthy
participants.
Method: Ten healthy asymptomatic males free from back pain, spinal
fracture or surgery were included, consisting of a young group (YG,
n = 5) and mature group (MG, n = 5). Axial T1-weighted magnetic
resonance images were obtained (1.5T Siemens, slice thickness
10 mm, TR/TE: 253/7.1 ms, rectangular field of view 80 %). Muscle
volumes (left and right sides) of erector spinae (ES), multifidus (M),
rectus abdominis (RA), psoas (PS) and lateral abdominal musculature
(LA) of the lumbar spine were measured using Analyze V. 11.0
software. The ratio of combined flexor volume (FV - RA, LA, PS) and
extensor volume (EV - ES, M) was calculated. Data were statistically
analysed using paired and independent t-test or their non-parametric
equivalent.
Results: Mean age was 22.4 years (± 0.9) for the YG and 51.0 years
(± 6.2) for the MG. Height or weight were not significantly different.
There were no significant differences between left and right sided
volumes for any muscle in the YG but the left RA was significantly
greater than the right in the MG. Muscle volume in the MG was
significantly reduced in left RA (by 19 %), left PS (by 21 %), right PS
(by 19 %), left M (by 21 %) and right M (by 23 %) compared to the
YG (100 %). FV was significantly reduced in the MG compared to
the YG, but EV was not. The ratio between FV and EV was not
significantly different between the YG and MG.
Discussion: Even though multifidus volume was reduced in the MG
compared to the YG, FV to EV ratio was not different, indicating that
the balance between flexor and extensor volume is maintained with
age in a healthy population. This ratio may not be maintained in back
pain patients, and the resulting imbalance could cause further dys-
function or pain recurrence. Loss of the specific stabilisation capacity
of multifidus with age may predispose to age related instability and
thus contribute to the development of associated lesions. Cause and
effect however is unknown at this time.
P71
AN ATTEMPT FOR LOW-DOSE MYELO-
TOMOSYNTHESIS
Takao Nakajima, Yong Kim, Kazuhumi Minami
Department of Orthopedic Surgery, Nippon Medical School, Chiba
Hokusoh Hospital, Inzai-City, Chiba, Japan
Objective: Since we reported an attempt for low-dose whole-spine
imaging to reduce exposure. In orthopedics, tomosynthesis is being
increasingly used as well, which combines digital image processing
and tomography techniques. We are also working to reduce patient
exposure by using low-dose imaging in tomosynthesis-based mye-
lography called myelo-tomosynthesis (MTS). This report introduces
our attempt for low-dose MTS and indicates the efficacy evaluation
results.
Subjects and Methods: We compared surface doses (SDs) between
front and lateral plain X-ray and MTS of the thoracic and lumbar
vertebrae at our hospital. Surface doses were calculated by the
Numerical Dose Determination (NDD) method. In addition, the
usefulness of MTS was compared to that of conventional myelogra-
phy (M-G), computed tomography myelography (CTM), or magnetic
resonance imaging (MRI). At our hospital, MTS involves use of a
0.1 mm Cu filter for total filtration during the imaging procedure and
an X-ray tube swing angle of 30�. The reconstruction technique after
the imaging procedure is the Filtered Back Projection (FBP) method.
The reconstruction filter is of the greatest thickness (Thickness ++)
(Metal 6). To facilitate visualization of reconstructed images even at a
low dose, specific signal components are enhanced by using an image
processing technique called Multi-objective Frequency Processing,
and the contrast and density are adjusted to optimize the images.
Results and Discussion: With plain X-ray, the front and lateral SDs
were 2.19 and 2.73 mGy for the thoracic vertebrae and 2.37 and
4.75 mGy for the lumbar vertebrae. With MTS, the front and lateral
SDs were 2.15 and 3.07 mGy for the thoracic vertebrae, and 2.73 and
3.90 mGy for the lumbar vertebrae. The SDs with MTS were
approximately 1/4 to 1/2 of the targeted depreciation values with plain
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S747
123
X-ray specified in the JART Guideline (1/8 to 1/4 of guidance levels
of International Atomic Energy Agency). The advantages of MTS are:
(1) enables tomography in various positions and even under various
dynamic stress thereby providing more detailed information; (2) more
useful than M-G in delineating lesions such as deformed joints,
destroyed bones, and vertebral canal stenoses; (3) less subject to metal
artifacts than CT and MRI; (4) requires a shorter imaging time and is
less distressing to the patient than CT and MRI. MTS at our hospital
has sufficiently reduced patient exposure and can be an effective
alternative to M-G.
P72
PORCINE MODEL FOR EARLY ONSET
SCOLIOSIS CREATED WITH A POSTERIOR MINI-
INVASIVE METHOD
WANG Bin, ZHENG Xin, QIU Yong, QIAN Bang-ping, SUN Xu,
ZHU Zezhang, YU Yang
Spine Surgery, Nanjing, China
Introduction: Nonfusion techniques for the treatment of EOS require a
reliable animal model to test new devices preclinically. However, cur-
rently available models either took a long tethering period for model
creation or had the spinal elements violated to a great degree, which
called for a reliable model created in a shorter period with less invasion.
Methods: This study included ten female Yorkshire pigs (age,
5-6 weeks; weight, 5-7 kg) in which scoliosis was created with posterior
asymmetric tethering at the left side from T5 to L3. At the index surgery,
three separated incisions was used and ipsilateral rib tethering from the
10th to 13th ribs were also performed without disruption of the spinal
elements. Progressive deformity was documented with monthly radio-
graphs. Frontal and sagittal profiles were assessed using the Cobb
method. After 8-week tethering, all the instrumentations were removed,
and the pigs were observed for an additional 8-week period with serial
radiographs to document progression of the deformity.
Results: All pigs developed rapidly progressive, structural, idio-
pathic-type curves with convex to the right in the lower thoracic
spine. The mean coronal Cobb angle was 29� immediately postop-
eratively and progressed to 65� after 8-week tethering period. After
removal of the tethering, the scoliosis progressed to 68� on average
(range, 58� to 78�). On the saggittal plane, a mean lordosis of 32� at
the thoracic spine and a thoracolumbar kyphosis of 63� was also
observed at final follow-up. Apical vertebra rotation increased from
12� postoperatively to 39� after 8-week tethering period.
Conclusion: Using a mini-invasive tethering method, a rapidly pro-
gressive spinal deformity can be created in immature pigs. This
method avoids violation of the spinal elements throughout the cur-
vature and provides an ideal EOS model with great growth potential
for further study of new nonfusion therapies.
Keywords: animal model, early onset scoliosis, nonfusion.
P73
BIOMECHANICAL COMPARISON
OF VERTEBRAL AUGMENTATION
WITH SILICONE AND PMMA CEMENT AND TWO
FILLING GRADES
Werner Schmoelz, Alexander Keiler, Felix Riechelmann, Tobias Schulte
Trauma Surgery, Innsbruck, Austria
Introduction: Vertebral augmentation with PMMA is a widely
applied treatment of vertebral osteoporotic compression fractures.
Subsequent fractures are a common complication, possibly due to the
relatively high stiffness of PMMA in comparison with bone. Silicone
as an augmentation material has biomechanical properties closer to
those of bone and might therefore be an alternative. The study aimed
to investigate biomechanical differences, especially stiffness, of ver-
tebral bodies with two augmentation materials and two filling grades.
Methods: Forty intact human osteoporotic vertebrae (T10-L5, mean
age 75.3 ± 13.9 years, mean trabecular BMD 74.4 ± 22.5 mg/ccm)
were evenly distributed in 4 groups. Wedge fractures were produced
in a standardized manner. For treatment, PMMA and silicone at two
filling grades (16 % and 35 % vertebral body fill) were assigned to
four groups. Each specimen received 5000 load cycles with a high
load range of 20-65 % of fracture force, and stiffness was measured.
Additional low-load stiffness measurements (100-500 N) were per-
formed for intact and augmented vertebrae and after cyclic loading.
Results: Low-load stiffness testing after cyclic loading normalized to
intact vertebrae showed increased stiffness with 35 % and 16 %
PMMA (115 % and 110 %) and reduced stiffness with 35 % and
16 % silicone (87 % and 82 %). After cyclic loading (high load
range), the stiffness normalized to the untreated vertebrae was 361 %
and 304 % with 35 % and 16 % PMMA, and 243 % and 222 % with
35 % and 16 % silicone augmentation. For both high and low load
ranges, the augmentation material had a significant effect on the
stiffness of the augmented vertebra (p = 0.021), while the filling
grade did not significantly affect stiffness (p = 0.17).
Conclusions: The results indicate that fractured vertebrae undergoing
vertebroplasty achieve a significantly lower stiffness using VK100
compared to PMMA. Both materials have higher stiffness results in
case of 35 % augmentation compared to 16 %, this difference was not
significant but more pronounced for the PMMA.
P74
IN VIVO PHARMACODYNAMICS OF P2K,
A PEPTIDE THAT REGULATES TGF-BETA
SIGNALLING ON DISC DEGENERATION
Young-joon Kwon, Je-wook Lee, Eun-joung Moon, Ok-soon Kim,
Hae-jin Kim
Department of Neurosurgery, Seoul, Korea (ROK/South Korea)
Purpose: In a previous study, we demonstrated that P2 K, a novel
peptide that regulates TGF-beta signaling, showed an anabolic effect
on degenerated disc using rabbit model.
The purpose of this study was to investigate in vivo pharmacody-
namics of P2K in rabbit degenerated disc and determines the maximal
effective dose in in vivo.
Materials and methods: In 15 New Zealand white rabbits, disc
degeneration was induced by annular needle puncture and confirmed
4 weeks after the puncture by the decrease in disc height in X ray.
Then the rabbits divided into 5 treatment groups according to P2K
dose (0, 3ug, 10ug, 30ug, 60ug). Three consecutive discs in each
rabbit were then treated with lactose (5 % in saline) or P2 K at var-
ious doses. Twelve weeks after treatment (16 weeks from initial
annular puncture), the regenerative activity in the disc was examined
by X-ray radiography, magnetic resonance imaging (MRI), and his-
tological analyses. Statistical analyses were performed by repeated
measures ANOVA, ANCOVA, and Mann–Whitney test.
Result: The disc height index (DHI) in X ray of P2 K treatment
groups were gradually increased during time course and increased
12 weeks after treatment, compared to control group. The P2K
S748 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
injection of dose 30ug per disc resulted in significant increase of
%DHI (p \ 0.001) during the time course, followed by 10ug/disc
(p \ 0.05). At 12 weeks after treatment, two doses of P2K (30 lg and
10 lg, sequentially) showed significant increase of %DHI, compared
to control group. The MR grade was significantly increased in 10 lg/
disc treated group (p \ 0.05). Histologic grades using H&E/Safranin
O stain were also improved in P2K treated groups and correlated with
the MR grade.
Conclusion: The results show that range of maximal effective dose of
P2K would be 10 to 30ug/disc. Based on these results, adjustment of
P2K dose would be important in maximizing the regulation of TGF
b1 signaling on degenerated disc.
CERVICAL SPINE
P75
FACETECTOMY IS MORE EFFECTIVE
THAN FORAMINOTOMY TO PREVENT
IATROGENIC FORAMINAL STENOSIS
AFTER PEDICLE SCREW FIXATION
IN THE CERVICAL SPINE
Akiyoshi Yamazaki, Tomohiro Izumi, Hirokazu Shoji, Yu Sato,
Tatsuki Mizouchi
Spine Center, Orthopaedic Surgery, Niigata, Japan
Introduction: The incidence of iatrogenic foraminal stenosis (IFS),
which is not directly attributable to cervical pedicle screw (PS)
insertion, is reported to be 0.6- 50 %. The use of posterior forami-
notomy is recommended for preventing IFS. However, in some cases,
IFS occurs even after foraminotomy. The purpose was to compare the
effectiveness of foraminotomy with that of facetectomy in preventing
IFS after PS fixation.
Methods: PS fixation was indicated in 43 patients for instability or
kyphotic deformities from C4/5 to C7/T1. Of these 43 patients (total
190 nerve roots in the fusion area), 16 underwent PS fixation without
foraminotomy, 17 underwent foraminotomy, and 10 underwent fac-
etectomy. The average patient age was 62 years. Investigated factors
included the incidence of IFS, Manual Muscle Test score worsening
by [ 1 grade, and the preoperative foraminal diameter on axial CT
images.
Results: The incidence of IFS was 4.3 % (5/117 roots; C5 in 2 patient, C6
in 1, and bilateral C8 in 1) without foraminotomy, 8.4 % (4/48 roots; C5
in 4 patients) with foraminotomy, and 0 % (0/25 roots) with facetectomy
(p = 0.197). Without foraminotomy, the average foraminal diameter in 5
roots with IFS was 1.3 mm (0.8- 1.7 mm), while that in 112 roots without
IFS was 3.6 mm (0.8- 7.1 mm) (p\ 0.001). Five out of 13 roots (38 %)
with foraminal diameter less than 1.7 mm presented IFS. With forami-
notomy, the average foraminal diameter was 1.7 mm (1.3- 1.8 mm) in 4
roots with IFS and 2.1 mm (0.5- 5.9 mm) in 44 roots without IFS
(p\ 0.05). Four out of 22 roots (18 %) with foraminal diameter less than
1.8 mm presented IFS even after foraminotomy. With facetectomy, the
average foraminal diameter was 2 mm (0.8- 4.6 mm). According to
receiver operating characteristic analysis, the cut-off value was estimated
as 1.7 mm without foraminotomy and 1.8 mm with foraminotomy.
Discussion: Foraminotomy is not sufficient to prevent IFS. In con-
trast, IFS did not occur after facetectomy. Foraminotomy primarily
decompresses the inlet of the foramen. Therefore, it may cause IFS by
creating rigid fixation, changes in sagittal alignment, or unexpected
posterior translation. However, facetectomy decompresses the entire
foramen from the inlet to the outlet, allowing clinicians to fully
observe the nerve roots. IFS occurred even after foraminotomy,
especially when the foraminal diameter was \ 1.8 mm. Therefore,
prophylactic facetectomy rather than foraminotomy is recommended,
especially at the C4/5 level.
P76
‘‘SKIP’’ CORPECTOMY IN TREATMENT
OF MULTILEVEL CERVICAL SPONDYLOTIC
MYELOPATHY CAUSING BY OSSIFIED
POSTERIOR LONGITUDINAL LIGAMENT
Alexander Barysh, Stanislav Kozyryev
Orthopedic, Kharkiv, Ukraine
Objective: According to existing literature sources, results of corp-
ectomy on one and two levels are usually considered to be good. At the
same time, multilevel corpectomy is associated with a high complication
rate, such as graft migration, screw and plate breakage, pseudoartrosis
and screw loosening. The skip corpectomy technique is one of modern
ways of decompression and stabilization of cervical spine in patients with
cervical spondylotic myelopathy (CSM) and ossified posterior longitu-
dinal ligament (OPLL). Theoretically it can lessen the rate of
complications, associated with grafts and implants. This retrospective
study evaluated the outcomes of skip corpectomy by clinical and radio-
logical criteria in patients with CSM causing by OPLL.
Methods: There were evaluated outcomes of 15 consecutive patients
(11:73.3 % men and 4:26.7 % women among them) who were treated
during 2008 - 2013 years. Age of patients was from 57 to 76 years.
All patients had undergone surgical treatment - subtotal corpectomy
of C4 and C6 vertebras, resection of osteophytes on C 5 vertebra,
decompression of spinal canal, interbody fusion with autografts from
iliac crest bone and ventral fixation by cervical plate of own con-
struction. The clinical outcomes we evaluated using JOA scale before
and after surgery, and at the final follow-up. We performed X-ray and
CT examination preoperatively and postoperatively accessing signs of
fusion by Bridwell and cervical lordosis.
Results: The mean preoperative JOA score was 12.2 ± 1.7, after
surgery it was 13,1 ± 0.8, at the final follow up it was 14.3 ± 2.2.
The cervical lordosis was 1.8 ± 10.5 degrees preoperatively,
16.4 ± 2.3 after surgery and 14.5 ± 6.5 degrees at the final follow
up. Fusion signs grade 1 had 4 patients, grade 2 was in 8 cases, grade
3 had 2 patients, grade 4 was in 1 case. We met the following
complications : transient dysphagia in 2 cases, C-5 nerve palsy in 1
case, C-7 partial screw pullout in 1 case, temporary hoarseness in 1
case. Two patients had pain in iliac crest donor site for 3 weeks.
Conclusion: Skip corpectomy is an effective technique in OPLL and
CSM treatment, evidenced by good fusion rate and proper clinical
outcomes. Preservation of the C-5 vertebra provide an additional
stability and strengthening of the construct.
P77
POSTOPERATIVE COMPLICATIONS
OF CERVICAL SPONDYLOTIC MYELOPATHY
Antonia Matamalas, Xavier Plano, Ferran Pellise,
Ana Garcia de Frutos, Jose Casamitjana
Orthopaedic Surgery, Barcelona, Spain
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S749
123
Objective: To assess the rate of complications associated with cer-
vical spondylotic mielopathy (CSM) surgery and to evaluate the
influence of the approach on complication rates.
Methods: A retrospective single-center study. All patients operated
because of CSM between 2005 and 2010 with at least one year fol-
low-up were reviewed. Demographic data; preoperative co-
morbidities; medical, surgical and mechanical complications and re-
intervention during follow up were collected in a standardized
manner.
Results: 237 surgeries on 221 patients (mean age 52.2 years; 66.5 %
men). 78.3 % of patients has at least one associated co-morbidity
(mean co-morbidities per patient = 2.07). The mean hospital stay
duration was 9.8 days (SD = ±8.3).
26.6 % of patients had complications during the postoperative period
(14.8 % minor and 11.8 % major complications). The most common
perioperative complications included respiratory insufficiency
(4.2 %), dysphagia (4.2 %) and urinary tract infection (3.4 %).
Wound complication rate was 6.8 %: of which 3.8 % were dehiscence
and 3 % infectious (2.1 % deep). Only one case of perioperative
worsening of myelopathy was detected (0.4 %).
Mechanical complication rate during follow-up was 3.8 % and 9.3 %
of patients needed a new surgery during follow-up (2.5 % debride-
ment; 6.3 % progression of myelopathy; 0.4 % instrumentation
failure). Mortality rate was 0.4 %.
When we compared anterior (n = 157) and posterior (n = 75)
approaches, 9.6 % and 16 % of patients had major complications.
Patients operated on by posterior approach were older (62.7 vs 55.8),
a larger number of levels of interventions (3.3 vs 2.2) and longer
hospital stays (11.6 vs 5.8 days). Compared with the anterior
approach, posterior approach patients had a higher incidence of
medical complications (p = 0.004), wound complications (p = 0.03)
and radicular complications (pain 8.1 % vs 1.3 %;p = 0.01 and
neurological impairments 5.4 % vs 0.6 %;p = 0.04). The most fre-
quently affected roots were C6 (1.9 %) and C5 (1.5 %).
We didn0t find differences between the number of levels of inter-
vention and different kinds of complications analyzed. Older patients
had higher rates of medical complications postoperatively
(p = 0.001).
Conclusions: One quarter of patients operated on because of CSM
developed some kind of postoperative complication. Older patients
had a higher risk of medical complications, while patients operated on
by posterior approach had a higher risk of wound complications.
P78
COMBINATION OF FUSION AND MOTION
PRESERVATION IN THE SURGICAL TREATMENT
OF DEGENERATIVE CERVICAL DISC DISEASE
Bank Andras, Szollosi Balazs, Varga Peter Paul
National Center For Spinal Disorders, Budapest, Hungary
Introduction: Our clinical study design was prospective, concur-
rently enrolled and single-center trial of the combination of fusion
(intervertebral cage with or without ventrofixation) and cervical disc
prosthesis implantation in the treatment of patients with multiple level
degenerative disc disease. The cervical disc arthroplasty become more
and more popular in the surgical treatment of the degenerativ cervical
disc disease. The goals of the cervical disc arthroplasty are to
maintain or restore intervertebral height, spinal balance and mobility
and to avoid adjacent segment degeneration. However, in most of the
patients with multisegmental degenerative disc disease the certain
segments show different stage of degeneration and instability. The
study was designed to investigate the clinical effects of the combi-
nation of cervical fusion and arthroplasty and to observe the stability,
range of motion, and the cervical spine sagittal balance in the follow
up period.
Materials and methods: Since December 2007 to September 2010,
24 patients with symptomatic cervical radiculopathy and/or myelop-
athy underwent surgery with this combined method. In 7 cases the
surgery involved two level, in 14 cases was three level, and 2 cases
was four level. At the follow-up period the patients pain, neurologic
function, and the radiographic parameters (range of motion at the
level of prosthesis and the adjacent segments, the intervertebral disc
height of the adjacent segments, lordosis of the whole cervical spine,
heterotopic ossification) was evaluated.
Results: Early clinical experiences are promising. The segment of the
prosthesis ultimately showed preservation of motion when compared
with preoperative levels. The preop. average ROM was 8.2� (flexion/
extension), the postop. average ROM 7.6�. The whole cervical spine
lordosis was preop. 1.7� the postop. 16.2�. We have no implant related
failure.
Conclusions: The most important potential advantages of this method
that we can treat the multisegmental degeneration in each segment
with the proper method including motion preservation and fusion, and
restore the sagittal balance of the cervical spine. Although early
results are promising, long-term follow up studies required to prove
its efficacy in the surgical treatment of the multisegmental degener-
ative cases.
P79
THE EFFICACY OF RHBMP-2 VERSUS ILIAC
CREST BONE GRAFT FOR POSTERIOR
C1-2 FUSION IN PATIENTS OVER 60 YEARS
OF AGE
Baorong He, Liang Yan, Dingjun Hao
Hong Hui Hospital, Xi’an Jiaotong University College of Medicine,
Xi’an, China
Few studies have specifically examined the efficacy of rhBMP-2/ACS
for posterolateral lumbar spine fusion. The purpose of this study is to
report on clinical outcomes, in elderly patients treated posterior C1-2
fusion with ICBG plus rhBMP-2/ACS versus ICBG alone. One
hundred and forty patients were enrolled in a prospective randomized
trail and underwent instrumented C1-2 fusion in patients over
60 years old. All the patients were divided into two groups based on
fusion material. The ICBG group consisted of patients who received
ICBG alone. The rhBMP-2/ACS group was composed of patients
with ICBG plus rhBMP-2/ACS. A comparison was made based on
OR time, EBL, LOS, clinical results, perioperative complication,
fusion rate, fusion time, and revision rates. There were no significant
differences in OR time, EBL, LOS and intraoperative surgical com-
plications between the two groups. The improvement in VAS, JOA
scores over the 2-year follow-up period was similar in both groups.
The fusion rate was 82.4 % (56/68) in the rhBMP-2/ACS group and
78.7 % (52/66) in the ICBG group (P = 0.782). The fusion time was
significantly greater in the rhBMP-2/ACS group (81.8 ± 29.4 days)
than in the ICBG group (92.9 ± 23.7 days, P = 0.034). There were
more wound complications requiring treatment in the rhBMP-/ACS
group (6, 8.8 %) versus the ICBG group (2, 3.0 %), although this was
not statistically significant (P = 0.118). the use of rhBMP-2/ACS for
posterior C1-2 fusion appears to generate relatively greater fusion rate
and fusion time, but there may be an increased risk of posterior
cervical wound complications.
S750 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
P80
MANAGEMENT OF TYPICAL AND ATYPICAL
HANGMAN’S FRACTURES
Christopher Beagrie, Eleanor Woolley, Rafid Al-Mahfoudh,
Rasheed Zakaria, Mark Radon, Robin Pillay, Martin Wilby
Neurosurgery, Liverpool, UK
Aims: Although most authors agree that Hangman’s fractures can be
managed conservatively a degree of uncertainty still exists. Variants
of fractures of the ring of the axis have been recorded but no agreed
classification system exists. Our aim was to retrospectively review
management and outcomes of these fractures and compare to the
existing literature.
Methods: Retrospective analysis of 282 patient records treated
between 2004 and 2013 with C2 cervical spine fractures was per-
formed. Forty-one patients with typical and atypical hangman’s
fractures of the C2 vertebra were identified. Typical hangman’s
fractures were defined by Francis et al. as traumatic spondylolisthesis
of the axis causing a bilateral pars interarticularis fracture[3]. Frac-
tures involving the posterior cortex of C2 on one or both sides have
been defined as Atypical. [4][5].
The radiological records were reviewed and graded by an independent
radiologist according to the modified Effendi system[1] (modified by
Levine[2]).
Results: Forty-one adult patients with a mean age of 59.7 years were
included (seventeen male and twenty-four females). There were
twelve (29 %) typical hangman’s fractures and twenty-nine (71 %)
atypical hangman’s fractures.
Five typical Hangman’s fractures (38 %) were managed with a rigid
collar and five (38 %) were managed with a halo orthosis. In the
atypical group, six (21 %) were managed with rigid collar, twenty
two (76 %) using halo orthosis and one (3 %) surgically.
Surgical fixation was performed in two patients with typical Hangmans
fractures, one for C3 associated injuries and one for progression of
fracture whilst in halo orthosis. One patient in the atypical fracture series
underwent surgery following failure of conservative management.
Bony union was achieved in all patients on radiological follow up. No
new neurological deficits were documented. Neck pain and stiffness
were more commonly reported in the atypical group with 9 (33 %)
experiencing mild-moderate symptoms compared to one (8 %) in the
typical group. Three atypical hangman’s fracture patients were lost to
follow up.
Conclusions: The management of atypical Hangman’s fractures are
very similar to the classically described bilateral pars fracture. The
majority of Hangman type fractures can be treated conservatively.
Radiological follow up is essential to identify cases of non union. In
our series three patients underwent surgical fixation after failure of
conservative management.
P81
CENTRAL CORD SYNDROME: DOES EARLY
SURGICAL INTERVENTION IMPROVE
NEUROLOGICAL OUTCOME?
Ciara Stevenson, Jonathan Warnock, Suzanne Maguire, Niall Eames
Royal Victoria Hospital, Belfast, UK
Central cord syndrome: does early surgical intervention improve
neurological outcome?
Background: Historically the treatment of central cord syndrome has
been conservative however recovery is often incomplete. Surgery
remains controversial and there is no uniform consensus in the lit-
erature about treatment.
Aim: To review management and outcomes of patients with central
cord syndrome in Northern Ireland in 1 year.
Methods: Patients were identified using the Fracture Outcome
Research Database cross-referenced with the spinal MDT register.
Information gathered included demographics, mechanism of injury,
length of hospital stay and functional status. ASIA scores calculated
at injury, pre-operatively, post-operatively and at follow up.
Results: 27 cords identified, 5 managed conservatively and 22 with
surgery. Average age 62 years. 85 % were male. 85 % of patients had
a simple fall with neck hyperextension.
Average Asia motor score in operated patients improved from injury,
pre-operatively, post-operatively and at follow up from 51, 81, 83 and
90 respectively. 86 % patients independent at follow up.
Average Asia motor score in conservative patients improved from
time of injury to day 10 from 57 to 86 however at follow up fell to 84.
Only 20 % were independent at follow up.
Patients operated on within 10 days of injury had improved motor
function compared with those operated on after day 10. 82 % of their
improvement occurred prior to surgery.
Conclusions: This review suggests that patients treated with surgery
have improved Asia scores and functional outcomes. Three patterns
of recovery have been identified and timing of surgery is crucial. For
the majority of patients operated on late, the role of surgery maybe to
prevent deterioration.
P82
CLINICAL OUTCOMES OF MULTI-LEVEL
POSTERIOR CERVICAL FORAMINOTOMY
FOR THE TREATMENT OF CERVICAL
RADICULOPATHY
Dong Chan Lee, Choon Keun Park, Dong Geun Lee, Jong Yang Oh,
Dong Hwan Lim, Dong Hwa Heo, Jang Hoe Hwang,
Hyoung Sub Kim, Huk Keun Lee
Neurosurgery, Suwon, Korea (ROK/South Korea)
Objective: The benefits of one-level posterior cervical foraminotomy
have been recognized by several papers. However, reports of the
efficacy of multi-level posterior cervical foraminotomy are rare. The
aim of this study was to analyze the surgical outcomes of multi-level
posterior cervical foraminotomy in patients with multi-level unilateral
cervical radiculopathy..
Material and Method: Forty six patients were surgically treated
with multi-level posterior cervical foraminotomy with or without
discectomy for cervical radiculopathy. All patients had radiculopa-
thy with or without neck pain. Among those 46 patients, 36 patients
could be followed-up for at least 3 year. The mean follow-up period
was 44.4 ± 10.9 months(ranged 36-64 months). Sex, age, symptom
period, preoperative and postoperative neck pain, motor weakness,
level of operation, and combined discectomy were analyzed. Clin-
ical outcomes were retrospectively assessed according to
VAS(visual analogue scale), NDI(neck disability index) and Odom’s
criteria.
Results: There were 32 men and 4 women. The mean age was
55.4 years old (range 42-71 years). The mean symptom period was
17.5 months (range 1-72 months). Ten patients had preoperative neck
pain. Four patient had transient postoperative neck pain. Eight patients
had preoperative motor weakness. Two level foraminotomy was
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S751
123
performed in 33 cases, three level in 2 cases and four level in 1 case. We
performed foraminotomy with discectomy in 14 levels. Clinically,
90 % patients had improved or resolved radicular symptoms. The
patients had taken foraminotomy with discectomy was better clinical
outcomes. The preoperative VAS for arm pain was 8.08 ± 0.69. The
mean postoperative VAS for arm pain was decreased to 1.82 ± 1.16.
The clinical outcome was excellent in 16 cases (44.4 %), good in 16
cases (44.4 %), fair in 3 case (8.3 %), and poor in 1 case (2.8 %). One
patient took ACDF at same level after 1 year. We confirmed that
foraminal space was widened by postoperative MRI in 32 cases. There
were no surgery-related complications in any cases.
Conclusion: Most patients treated with the posterior cervical for-
aminotomy have good to excellent outcomes. It appears to be a good
alternative procedure for carefully selected patients with unilateral
cervical radiculopathy and avoids a fusion of the disc space. Espe-
cially, we suggest that the operator must make efforts to seek a
possible ruptured disc.
P83
POOR OUTCOME AFTER WHIPLASH INJURY.
A STUDY WITH 4 YEARS FOLLOW UP
Georgios Mouzopoulos, Ioannis Skevofilax, Aris Adraktas,
Aggeliki Paragi, Georgios Nomikos, Vasilios Vasiliadis
Orthopaedic Department of Chios Hospital, Chios, Greece, Chios,
Greece
Purpose: The aim of our study was to identify the prognostic factors
associated with a poor response to treatment in the early stages of a
whiplash injury of cervical spine.
Methods: A study cohort of 231 patients with acute or subacute
whiplash injury, presenting to our department, during the period
between January 2002 and May 2008, were investigated for factors
associated with poor outcome according to the Canadian Back
Institute Questionnaire (CBIQ) score. Demographic data were col-
lected. Lag time between injury date and presentation for treatment
and initial pain intensity according to VAS score were also evaluated.
All patients were assessed on admission and 4 years after injury.
Statistical analysis was performed by statistical packet STATA 8.0.
Results: Logistic regression analysis revealed the following prognostic
factors associated with a negative outcome: 1) older age [ 65ys (odds
ratio = 2.01; 95 %CI:1.16-3.49), 2) female gender (odds ratio = 3.91;
95 %CI:2.12-4.79), 3) increasing lag time between injury date and pre-
sentation for treatment, more than 5 days (odds ratio = 2.81;
95 %CI:1.56-3.71), 4) higher initial pain intensity, more than 7 according
to VAS score (odds ratio = 1.91; 95 %CI:1.06-3.69).
Conclusion: Older age, female gender, late therapy onset and intense
initial pain are important prognostic factors for a 4-year handicap
after acute whiplash.
P84
MOTION PRESERVING PROCEDURE
FOR THE TREATMENT OF HANGMAN’S
FRACTURE
Gohsuke Hattori, Takahiro Miyahara, Hisaaki Uchikado,
Motohiro Morioka
Department of Neurosurgery, Kurume University School of
Medicine, Kurume, Fukuoka, Japan
Object: Opinions have varied regarding the optimal treatment of an
unstable Hangman’s fracture. C2 pedicle screw instrumentation is a
biomechanically strong fixation witch although done through a simple
posterior approach. The purpose of this study is to determine the
effectiveness of C2 pedicle screw fixation on Hangman’s fracture
management.
Methods: This prospective study included 6 consecutive patients with
displaced type II or IIA traumatic spondylolisthesis of the axis. There
were three males and three females with mean age of 58 years at
surgery. The cause of injury was a road traffic accident in 3 patients
and a fall from height in 3 patients. All patients had a single stage
reduction and direct transpedicular screw fixation through the C2
pedicles. Two patients required additional fixation with the C3 lateral
mass screw. During follow-up, clinical evaluation and plain X-rays
were performed at each visit; at 3, 6, and 12-month follow-up,
additional dynamic lateral flexion/extension views and a CT scan
were performed.
Results: Mean follow-up period was 37 months (range of
15-52 months). At final follow-up, all patients were asymptomatic
and regained a good functional outcome with no limitation of range of
motion; all the patients showed solid union with no implant failure.
There were no neurological complications. At 6-month follow-up, CT
evaluation showed fusion in all patients and an adequate position of
12 screws.
Conclusions: Transpedicular screw fixation through the C2 pedicles
is a safe and effective method in the treating type II traumatic
spondylolisthesis of the axis, resulting in good clinical and radio-
logical outcomes. Adequate reduction was achieved and motion
segments were preserved with its use.
P85
ASSESSING QUICKNESS OF UPPER LIMB
AND HAND FUNCTION FOR PATIENTS
WITH CERVICAL SPINAL CORD INJURY
WITHOUT BONE INJURY USING SIMPLE TEST
FOR EVALUATING HAND FUNCTION
Jun Shinbo, Masaya Mimura, Hiroaki Sameda, Sumio Ikenoue,
Kan Takase, Eiko Hashimoto, Aya Kanazuka, Takahiro Enomoto
Orthopedic Department, Funabashi Municipal Medical Center,
Funabashi, Japan
Objective: It has been reported that in assessing tools for evaluating
spinal cord injury (SCI) outcomes, further validation studies are
required to identify the most appropriate tools for specific targets in a
human SCI study. Moreover, there are few reports on evaluation
methods of upper limb and hand motor skill including manual speed.
Simple test for evaluating hand function (STEF) is designed in Japan
in 1974 to objectively evaluate the speed of carrying objects to an
arranged area and inserting sticks into holes or turning over cloths,
which has come to the market in Japan. The aim was to evaluate
quickness of upper limb and hand function for patients with cervical
spinal cord injury without bone injury (CSCIWBI) using STEF and
compare the improvement rate of quickness between surgical and
conservative treatment retrospectively.
Materials-Methods: Eighteen patients with CSCIWBI were enrolled.
Ability of manipulating the objects by the upper limb and hand was
assessed using STEF (The maximum score is 100 points.) at each
hand at 2, 4, 6, 8, 12, 24 and 24 weeks. Laminoplasty was performed
3 weeks after injury in cases with delayed neurological recovery. At
2 weeks after injury, all the upper arms were categorized based on the
S752 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
treatment and STEF score (border point: 60) into four groups: Con-
servative-Low STEF group (CL), High STEF group (CH), Operative-
Low STEF group (OL) and Operative-High STEF group (OH). The
rate of improvement was calculated as the amount of STEF score
improvement or deterioration per week. Data analyses were per-
formed using Mann–Whitney U-test.
Results: The numbers of upper limb in CL, CH, OL and OH were 3,
9, 17 and 7 respectively. There was no statistical difference of the average
STEF score in comparison between the CL and OL at all the examined
time points. No statistical difference of the average STEF score between
CH and OH was also found in comparison at all the examined time points.
The average rate of improvement from 2 to 4 weeks in CL and OL were
9.83 and 8.47 respectively and no statistical difference was found
between them. Whereas, the average rate from 4 to 48 weeks in the CL
and OL were 0.24 and 0.78 respectively and statistical difference was
observed between them. (P \ 0.05).
Conclusion: STEF could be a useful tool for the evaluation of upper
arm function of patients with CSCIWBI. Surgical treatment could
have positive impact on the improvement of quickness of upper limb
and hand function.
P86
PEDICLE-HINGED UNILATERAL POSTERIOR
ARCH RECAPPING TECHNIQUE FOR DUMBBELL-
SHAPED CERVICAL SPINAL CORD TUMORS
Kazuya Kitamura, Tateru Shiraishi, Ryoma Aoyama,
Jun-ichi Yamane, Ken Ninomiya, Seiji Ueda
Department of Orthopedic Surgery, Hiratsuka City Hospital,
Kanagawa, Japan
Introduction: For safe and secure excision of cervical spinal cord
tumors, we have performed muscle-preserving Unilateral Posterior
Arch Recapping Technique (UPART) in 11 cases, in which unilateral
posterior arches pivoted on the lateral gutter of the laminae with all
their attached muscles preserved. For dumbbell-shaped cervical spinal
cord tumors, anterior or posterior one-way approach can injure vital
organs including vertebral artery and spinal cord. To prevent these
vital complications and excise the tumor securely, we developed a
new procedure in which the unilateral posterior arches pivoted on the
divided pedicles (P-UPART) and macro-totally excised 4 dumbbell-
shaped cervical neurinomas.
Methods: Microscopic surgical technique: (UPART) The spinous
processes were sagittaly split and lateral gutters were created on the
laminae with the attached muscles undisturbed. Then, the epidural
space was exposed by opening unilateral laminae. After excising
tumor, the opened unilateral laminae were reduced to their counter-
parts with stitches. (P-UPART) First, by antero-lateral approach, the
outer wall of the foramen transversarium was removed to dislodge the
vertebral artery, then the inner wall, the pedicle, was divided after
excising anterior tumor component. Second, by posterior approach,
unilateral laminae pivoted on the divided pedicle after sagittally
splitting the spinous processes. After excising posterior tumor com-
ponent, the opened laminae were reduced in the same way as UPART.
Evaluation: This study included 11 cases of UPART and 4 cases of
P-UPART. Cervical curvature and flexion–extension range of motion
were measured on plain X-rays, and bone union examined on CT. Cross-
sectional area of the deep extensor muscles on the affected side was
compared with that on the opposite side on postoperative axial MRI.
Results and discussions: All tumors were successfully excised.
Postoperative MRI showed no evidence of muscle damage.
Undamaged muscles and landmarks can make revision surgeries safer
as well as minimize dead space formation and incidence of infection.
Furthermore, P-UPART has following advantages; 1. the anterior
tumor component is securely excised with the vertebral artery kept in
control, 2. the unilateral laminae opened on the divided pedicle pro-
vide wider epidural space for safer tumor excision avoiding spinal
cord damage, 3. the posterior musculature is kept completely undis-
turbed as lateral gutter is unnecessary.
P87
POTENTIAL USE OF DIFFUSION TENSOR IMAGING
FOR LEVEL DETERMINATION IN MULTILEVEL
CERVICAL SPONDYLOTIC MYELOPATHY
Keith Luk, Xiang Li, Jiao-Long Cui, Kin-Cheung Mak, Yong Hu
Orthopaedics and Traumatology, Pokfulam, Hong Kong
Background: Cervical spondylotic myelopathy (CSM) resulting from
multilevel canal stenosis commonly presents with complex neuro-
logical signs which makes level localization difficult. While Magnetic
Resonance Imaging (MRI) could identify the level(s) of compression
anatomically, it is unable to reveal the pathological changes inside the
compressed cord leading to discrepancies between the MRI level and
the clinical findings. Diffusion tensor imaging (DTI) is recently found
to be able to assess the microstructural changes of the white matter
caused by cord compression and may be a useful tool for level
determination in multilevel CSM.
Method: 16 CSM patients with multilevel compression were recrui-
ted for this study. The level(s) responsible for the clinical symptoms
were determined by: (1) a detailed clinical neurological examination,
(2) T2-weighted MRI, and (3) DTI analysis (Orientation Entropy,
OE). On the T2 W MRI the anterior-posterior compression ratio
(APCR) of the compressed cord and the presence of a high-intensity
signal (HIS) were used to determine the affected level(s). The level
estimation results from T2 W MRI and DTI analysis were correlated
to that of the clinical neurological examination on a level-to-level
basis. The agreement rate, sensitivity and specificity were calculated.
Results: When correlated with the clinical level determination, the
OE based DTI analysis was found to have higher agreement rate than
the APCR (80.00 % versus 77.5 %) but they have almost equal
sensitivity (81.58 % versus 78.26 %) and specificity (59.09 % versus
59.09 %). The HIS has the highest agreement rate (95.45 %) and
specificity (95.45 %) but the lowest sensitivity (58.33 %).
Conclusion: DTI can be a useful tool to determine the pathological
spinal cord levels in multilevel CSM. This information from OE based
DTI analysis, in addition to the clinical neurologic assessment, should
help the spine surgeons in deciding the optimal surgical strategy.
P88
ANATOMIC FEASIBILITY OF C2 PEDICLE
SCREW FIXATION: A MULTIDIMENSIONAL
COMPUTED TOMOGRAPHY STUDY
Lauren Burke, Anthony Ho, Timothy Wagner, Joseph O’Brien,
Warren Yu
O’BrienOrthopaedic Surgery, Washington, USA
Objective: Anatomic variability of the C2 pedicle is well documented
and poses a challenge for C2 fixation. The use of multidimensional
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S753
123
computed tomography (CT) is not widely used, but may be an asset to
preoperative planning. This study evaluated the suitability of C2 pedicle
screws by using Osirix software to change the gantry angle of CT angi-
ograms in order to measure the anatomic dimensions of the C2 pedicle.
Methods: Retrospective review of CT angiograms of the head and
neck from 47 consecutive trauma patients at our institution. Data
collection included length and width of each C2 pedicle from 47
patients, allowing 94 samples, by 3 independent observers. This was
performed using Osirix (Pixmeo, Switzerland), a DICOM viewer that
allows navigation and visualization in multidimensional imaging,
such as 3D, which was utilized here. Vertebral anatomy was also
studied to determine if aberrant anatomy would preclude pedicle
fixation. Statistical analysis was performed.
Results: Of the 47 consecutive CT angiograms that were reviewed, 20
were of female patients and 27 were male. Overall mean C2 pedicle
width and length were 8.272 ± 1.364 mm and 27.052 ± 3.471 mm,
respectively. Gender-specific measurements were also determined.
The average width and length of pedicle in females was
8.040 ± 1.262 mm and 27.241 ± 2.731 mm, respectively. The
average width and length of pedicle in males was 8.444 ± 1.414 mm
and 26.913 ± 3.933 mm, respectively. The gender difference was
statistically significant for width (p = 0.012) but not for length
(p = 0.41). 98 % and 97 % of pedicles could tolerate a 3.5 mm and
4.0 mm screw, respectively, based on width. Only three patients had
vertebral anatomy that precluded screw length greater than 14 mm.
Conclusion: Careful preoperative planning is imperative for instru-
mentation at C2. Fine-cut, noncontrast CT is a useful tool to delineate
anatomy; however, the axis of images is not always along the ana-
tomical axis of the vertebra in question. With multidimensional CT or
3D imaging, we found that over 90 % of patients could tolerate both
3.5 mm and 4.0 mm pedicle screws at C2. Only 6 % of patients (3 of
47) have vertebral anatomy that precludes the use of screw lengths
greater than 14 mm. We conclude that the C2 pedicle may be more
tolerant of fixation than previously reported.
P89
CERVICAL MULTIFIDUS CONTRACTION IS
ASSOCIATED WITH ISOMETRIC CONTRACTION
OF SHOULDER MUSCLES
Leila Rahnama, Asghar Rezasoltani, Farhang Noorikochi,
Minoo Khalkhali, Alireza Akbarzadeh Baghban
Physiotherapy, Tehran, Iran
Background: Deep neck muscles provide the stability of cervical
spine either in rest or during neck movements. But whether it is
activated during upper extremities’ task to provide the stability of the
neck is unknown to us.
Objective: The aim of this study is ultrasonographic evaluation of
cervical multifidus (CM) thickness in response to isometric contrac-
tion of shoulder muscles.
Methods: A total of 23 healthy subjects were participated voluntarily
in this cross sectional study. Ultrasonographic imaging of CM has been
taken at level C4 while subjects were at rest and during 25, 50, 75 and
100 % maximal voluntary contraction of right shoulder muscles.
Results: Our results showed CM thickness increased as isometric
contraction of shoulder muscles increased (P = 0.00). This changes
of thickness was also larger at right CM (P = 0.047). However there
was no significant difference among effects of force directions on the
muscle thickness (P [ 0.05).
Conclusion: Cervical multifidus is contracted in isometric contraction
of shoulder muscles to provide the stability of cervical spine. It may
lead to design an indirect method for CM training in conditions in
which the direct contraction of CM is impossible or prohibited
because of pain or injury.
P90
DEGENERATIVE CERVICAL KYPHOTIC
DEFORMITY RECONSTRUCTION. IS RADICAL
SURGICAL CORRECTION EFFECTIVE?
Lukas Bobinski, John Michael Duff, Marc Levivier
Neurosurgical Department Lausanne, CHUV, Lausanne, Switzerland
Background and aims: Severe, fixed degenerative cervical deformity
is a rare condition. There are no current guidelines how to treat this
challenging disease. The goal of this report was to review the surgical
strategy, technique and the outcome in 5 patients after surgical
correction.
Methods: Among 14 retrospectively reviewed cases of severe cervical
kyphotic deformity, 5 (4 man and 1 women) were due to severe
degenerative changes. The average age was 66 years (49-78). All
subjects presented with signs of myelopathy and were treated with two
stage 360� correction. The Ishihara index and the Cobb angle at the apex
of deformity were measured on pre- and postoperative images. The
mJOA myelopathy score was calculated before surgery and during
clinical follow-up. The anterior approach (two or three level corpec-
tomy) was performed to achieve ventral release, decompression and
height restoration of anterior column. Anterior plating was used for
fixation. In the second stage of correction we used posterior instru-
mentation with pedicle screws (inserted using 3D fluoroscopy with
navigation) with compression across the construct to shorten the pos-
terior column. In one case, at the level of C4/C5 and C5/C6 we
performed posterior osteotomy to enhance correction. Each case was
under neurophysiologic surveillance, which remained unchanged.
Results: The mean clinical and radiological follow-up was 6 months
(1-12 months). The mean preoperative mJOA score improved from
average 13.2 (10-16) to 15.2 at follow-up (10-18).
In four patients we achieved the average correction of 12 points
measured by Ishihara index. One patient improved from -9 to plus 22
but during 6 months of the follow-up lost 11 points of correction. The
average pre-operative Cobb angle changed from kyphotic 17.1� to
kyphotic 4.2�.
Conclusions: Degenerative, fixed, cervical kyphotic deformity with
myelopathy requires complex treatment including: decompression,
anterior column height restoration and shortening of posterior column.
The 360� procedure enable all of these steps. The use of cervical pedicle
screws provides biomechanical advantage, which help maintain the
correction. Despite the fact we did not achieve full correction to lordosis,
our clinical outcome was good. However, these findings require long
term follow-up to ensure that deformity correction is maintained.
P91
SELECTIVE LAMINOPLASTY FOR CERVICAL
SPONDYLOTIC MYELOPATHY: A COMPARATIVE
STUDY WITH A MINIMUM 5-YEAR FOLLOW-UP
Minori Kato, Hiroaki Nakamura, Koji Tamai, Kazunori Hayashi,
Akira Matsumura, Sadahiko Konishi
Orthopaedic Surgery, Osaka, Japan
S754 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Purpose: Less invasive methods for laminoplasty such as selective
decompression laminoplasty decrease postoperative complications
and are reportedly effective for treating cervical spondylotic mye-
lopathy (CSM). To our knowledge, no comparative study has
evaluated the medium-term clinical outcome of selective laminopl-
asty vs. conventional C3-7 laminoplasty. The purpose of this study is
to examine the medium-term clinical outcome of selective lamin-
oplasty (C4-7 laminoplasty and C3-6 laminoplasty) in comparison
with conventional C3-7 laminoplasty for treating CSM over a mini-
mum follow-up of 5 years.
Methods: Medium-term (minimum follow-up: 5 years) clinical out-
comes of selective (C4-7 and C3-6) for CSM were compared with
those of C3-7 laminoplasty in 73 CSM patients. The extent of lam-
inoplasty was C3-7 in 42 cases (Group A), C4-7 in 16 (Group B), and
C3-6 in 15 (Group C). Clinical outcomes were evaluated by com-
paring the Japanese Orthopedic Association (JOA) Scores, axial
symptom (neck pain), and X-ray findings [cervical sagittal alignment
and range of motion (ROM) of cervical spine] before, at 2 years after
surgery, and at the final follow-up among 3 groups.
Results: Neurological recovery following selective laminoplasty (C4-
7: 51.9 % and C3-6: 53.4 %) was similar to that of C3-7 laminoplasty
(59.8 %). Among all the cases, the postoperative axial pain was
observed in 11 patients, with its incidence being 15.1 % at 2 years
after surgery. At final follow-up, 9 patients had postoperative axial
pain (12.3 %). In Group A, 9 patients had postoperative axial pain
2 years after surgery and 7 patients had axial pain at the final follow-
up. In Groups B and C, only 1 patient had postoperative axial pain at
2 years after surgery and at final follow-up. The percentage of cer-
vical spine ROM retained after surgery was significantly higher in
Groups B (59 %) and C (63 %) than in Group A (48 %) at final
follow-up. C4-7 laminoplasty retained the muscle attachments on the
C2 spinous process, which helped in maintaining cervical alignment
(4� increase in cervical lordosis).
Conclusions: Medium-term neurological recovery following selec-
tive laminoplasty was satisfactory compared with that following
conventional C3-7 laminoplasty. In addition, selective laminoplasty
decreased axial pain (neck pain) and ameliorated restriction of the
cervical spine ROM. Selective laminoplasty was effective in
improving the surgical outcomes in CSM patients, and medium-term
results were satisfactory.
P92
CERVICAL INJURIES - A TEN YEAR EXPERIENCE
FROM BELFAST, NORTHERN IRELAND
Rakesh Dhokia, Niall Eames
Royal Victoria Hospital, Belfast, UK
Objectives: To record our experience in the management of cervical
trauma. In particular compare the patterns of management of Atlanto-
axial, Sub-axial and isolated PEG injuries.
Methods: A retrospective review of the Fracture Outcome Research
Database (FORD) for Northern Ireland (NI). We reviewed 2395
patients admitted with cervical injuries to Royal Victoria Hospital,
Belfast, between January 2000 and December 2010. Cervical trauma
represented a mean 46 % of all spinal trauma admissions per year.
1251 were male and 783 female. 33 % patients were aged 65 + .
Results: NI population has increased 9 %, (1.81 million, 2011), There
is no significant increase in cervical trauma admissions. There is no
significant change in conservative (71 %) and surgical (29 %) man-
agement. The average proportion per year of Atlanto-axial trauma
was 31 % and Subaxial trauma was 69 %. There was a total of 365
PEG and associated segment injuries. Of these 266 were isolated PEG
fractures (Mean,24/year). Those treated conservatively 182(68 %)
and Surgical 84(32 %). Surgical treatment was 51 Halo, 4 Anterior
and 29 posterior fixations. All isolated PEG fractures surgically fixed
were aged under 65. For isolated PEG fractures the Mean age of
surgical fixation was 42 and those treated conservatively 69.
Conclusions: Cervical trauma admissions in NI represent a steady but
significant proportion of spinal trauma. In cases of isolated PEG
fractures all patients aged greater than 65 have been treated conser-
vatively with a cervical orthotic and surgical fixation has been
employed to patients aged 65 or under. Surgically treated patients
with multi segment atlanto-axial injury aged over 65 had posterior
fusion.
P93
IS IT SIGNIFICANT TO PRESERVE C7 OR C6
POSTERIOR ARCHES WITH THEIR
ATTACHMENTS OF NUCHAL LIGAMENT
FOR MAINTAINING CERVICAL CURVATURE
AND REDUCING NECK PAIN AFTER CERVICAL
LAMINOPLASTY?
Ryoma Aoyama, Tateru Shiraishi, Junichi Yamane, Ken Ninomiya,
Kazuya Kitamura, Satoshi Nori, Seiji Ueda, Ukei Anazawa,
Hiraku Hotta, Takeru Arai
Orthopaedics, Chiba, Japan
Introduction: Purpose of this study is to elucidate significance of
preserving C7 or C6 posterior arches with their attachments of the
nuchal ligament to maintain cervical curvature and to reduce neck
pain after posterior cervical laminoplasty. Previous papers, which
emphasized the significance of C7 preservation, compared results
between C3-7 laminoplasty sacrificing 5 extension units of the spi-
nous process and its attached muscles bilaterally and C3-6
laminoplasty sacrificing 4 units. Their study designs were inadequate
because the former was more invasive to cervical extension mecha-
nism than the latter. Avoiding the influence of surgical invasion, we
compared surgical results between the groups, each of which had the
same number of extension unit sacrificed.
Materials and Methods: Since 2002, 77 patients with cervical
spondylotic myelopathy (CSM) underwent adjacent two-level or one-
level laminoplasty. Among 32 patients who underwent two-level
laminoplasty sacrificing 2 extension units, attachment of nuchal lig-
ament was compromised in 10 patients (N2) while preserved in the
remaining 22 (P2). Among 45 patients who underwent one-level
laminoplasty sacrificing one unit, attachment of nuchal ligament was
compromised in 7 patients (N1) while preserved in the remaining 38
(P1). To evaluate surgical outcomes, Japanese Orthopaedic Associa-
tion (JOA) scores and Visual Analog Scale (VAS) were recorded for
each patient pre- and postoperatively. On the lateral radiographs with
the neck in neutral position, C2-7 angles were measured pre- and
postoperatively according to Cobb’s method.
Results: Improvement rate calculated with JOA scores averaged
63.7 % for N2, 43.2 % for P2, 48.3 % for N1, and 40.7 % for P1
respectively. Pre- and postoperative VAS scores of neck pain aver-
aged 2.0 and 0.6 for N2, 1.3 and 0.6 for P2, 1.3 and 1.3 for N1, and
2.7 and 1.6 for P1 respectively. Pre- and postoperative C2-7 angles
averaged 5.3� and 7.7� for N2, 11.4� and 11.5� for P2, 0.3� and 4.5�for N1, and 12.5� and 14.8� for P1 respectively. There was no sta-
tistical difference in pre- and postoperative JOA scores, VAS scores,
and C2-7 angles between the groups.
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S755
123
Conclusion: Preservation of the integrity of the cervical posterior
arches with their attachments of the nuchal ligament does not have
significant influence over postoperative neck pain and cervical curvature.
P94
IS CERVICAL LAMINOPLASTY REALLY ABLE
TO PRESERVE THE MOTION OF CERVICAL
SPINE? : MINIMUM 2 YEARS FOLLOW-UP
AFTER OPEN-DOOR LAMINOPLASTY
AND ADJACENT SEGMENT DEGENERATION
Sang Gu Lee, Keun Lee, Seong Son, Chan Woo Park,
Woo Kyung Kim
Neurosurgery, Gachon University, Gil medical center, Incheon, Korea
(ROK/South Korea)
Introduction: Several studies have reported on the decrease of range
of motion (ROM) associated with laminoplasty. The purpose of this
study was to compare the changes in ROM of whole cervical spine,
laminoplasty segment and adjacent segment after cervical unilateral
open-door laminoplasty between OPLL(ossification of posterior lon-
gitudinal ligament) and CSM (cervical spondylotic myelopathy) and
evaluate the adjacent segment degeneration in cranial and caudal
aspect of laminoplasty segment.
Material and Method: 41 patients (33 males and 8 females, mean
age: 53.2 years) who underwent unilateral open-door laminoplasty
were enrolled. The average follow-up period was 46.2 months. 22
patients had OPLL and 19 patients had CSM. Radiography was per-
formed before surgery, at 1-year follow-up and at the last follow-up. A
retrospective radiologic review of cervical alignment in the neutral and
flexion–extension view were measured by the Cobb method.
Results: Cervical ROM was decreased after laminoplasty from
37.2 ± 9.0� at preoperative state to 28.5 ± 2.6� at 1-year follow-up,
25.9 ± 13.1�at the final follow-up, showing a significant decrement of
11.2�(30.1 %). Laminoplasty segment ROM was decreased from
28.1 ± 8.3� at preoperative state to 18.3 ± 8.4� at 1-year follow-up,
16.2 ± 8.1� at the final follow-up. Upper segment ROM was 4.7 ± 2.6�at preoperation, 4.9 ± 4.0� at 1-year follow-up, 5.7 ± 4.1� at last follow-
up and this decrement was not significant statistically. Lower segment
ROM was 5.4 ± 2.5� at preoperation, 7.5 ± 2.6� at 1-year follow-up and
9.4 ± 3.0� at the last follow-up. 4 cases developed postoperative ky-
phosis (OPLL 3 vs. CSM 1) and 13 cases showed interlaminar bony
fusion at the last follow-up (OPLL 9 vs. CSM 4).
Conclusions: The study about ROM after cervical laminoplasty
showed that the postoperative cervical ROM decreased notice-
ably(30.1 %). Laminoplasty segment became stiff and adjacent
segment received more abnormal stress which increased more motion
in the caudal adjacent segment than in the cranial segment. Fortu-
nately, none of them developed into adjacent segment disease and
needed additional operation.
P95
RECONSIDERATION OF LAMINECTOMY
REGARDING THE PRESERVATION
OF THE SPINE CONSTRUCTION IN PATIENTS
WITH CERVICAL MYELOPATHY
Tatsuya Ohtonari, Nobuharu Nishihara, Katsuyasu Suwa, Taisei Ota,
Tsunemaro Koyama
Department of Spinal Surgery, Brain Attack Center Ota Memorial
Hospital, Fukuyama, Japan
Objective: To present a positive outlook for the replacement of open-
door laminoplasty, developed by Hirabayashi in 1977, by a lami-
nectomy that allows for mioarchitectonic preservation. Until recently,
we have performed open-door laminoplasty on patients with cervical
myelopathy. The concern about excessive stripping of the posterior
cervical muscles has led us to reconsider the long established
approach and change to the laminectomy that pays due attention to
the preservation of the cervical spine construction. This presentation
aims to introduce our surgical method and to report its short- and mid-
term results. We also report the mid-term results of open-door lam-
inoplasty to hint at the prospect of its outcome based replacement by
the laminectomy.
Methods: This laminectomy was performed on a total of 19 patients
with cervical myelopathy since February 2010, 16 were followed up
(10 males and 6 females, age 68.8 ± 9.1 years). The details regarding
the diseases of these patients were as follows: spondylosis, 7 cases;
canal stenosis, 8 cases; and discopathy, 1 case. The median value of
the preoperative JOA score was 12.0 (range: 3-16). The surgical
procedure was the following. Pursuant to a midline skin incision, a
paramedian approach to the symptom dominant side was taken to
strip the posterior cervical muscles up to the medial line of the facet
joint, while preserving the continuity of the nuchal ligament. The
spinous process in the target area for decompression was cut, and the
cervical muscles on the contralateral side were removed just slightly
beyond the edge of the cut section of the spinous process. Laminec-
tomy was performed with deviation to the dominant side of symptom.
Results: The median value of the JOA scores in the early or middle
postoperative phase (mean 218.3 days, range: 99-463 days) has
improved to 15.0, and the recovery rate of the JOA scores was
46.9 %. On the other hand, 60 patients with cervical myelopathy due
to non-OPLL underwent laminoplasty. Of these, 44 were followed
(mean 892.9 days, range: 311-2048 days, the median value of the
preoperative JOA score was 12.0) and the recovery rate of the JOA
scores was 52.9 %.
Conclusion: The laminectomy that enables the preservation of the
cervical spine construction might turn out to be the more preferable
one with less damage to the posterior cervical muscles if the mid- and
long-term outcome proves to be equivalent to that of open-door
laminoplasty.
P96
RELATIONSHIPS BETWEEN SURGICAL
OUTCOMES OF LAMINOPLASTY
AND POSTOPERATIVE RANGE OF MOTION
OF THE CERVICAL SPINE IN PATIENTS
WITH CERVICAL SPONDYLOTIC MYELOPATHY
Yuto Ogawa, Morio Matsumoto, Masaya Nakamura, Ken Ishii,
Yoshiaki Toyama
Department of Orthopedic Surgery, Saitama-shi, Japan
Several factors related to neurological recovery after expansive
laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM)
have been reported. However, an impact of postoperative range of
motion(ROM) of cervical spine on surgical outcomes has not been
addressed. This study was retrospectively conducted to elucidate
relationship between postoperative cervical ROM and surgical out-
comes of ELAP for CSM.
S756 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Methods: Between 1993 and 2011, 163 patients with CSM were
operated and followed for at least 1 year. To exclude surgery-related
factors and other factors unrelated to this disease which might affect
surgical outcomes, patients with CSM whose symptoms were
improved or unchanged after surgery were included into analyses
(130 patients).
Japanese Orthopedic Association score (JOA score), recovery rate
(RR: (postoperative JOA score - preoperative JOA score)/(17 -
postoperative JOA score) x 100), age at the time of surgery,
gender, preoperative morbidity period, ROM of cervical spine,
diminution rate of ROM (DR: 100 - postoperative ROM/preoper-
ative ROM x 100), alignment of cervical spine, level of affected
segment and antero-posterior diameter at affected segment, number
of segments where compression of spinal cord was observed were
assessed. Parameters were assessed before and 1 year after surgery.
Results: Preoperative mean JOA score of 9.8 ± 2.7 points improved
to 13.8 ± 2.3 points at 1 year after surgery. Mean RR was
50.6 ± 32.0 %. Significant correlation with RR was observed in age
(p \ 0.001), preoperative morbidity period (p = 0.04), postoperative
ROM (p = 0.02), and DR (p = 0.006). Significant difference in RR
was not observed in any categorical parameters. Multilinear regres-
sion analysis using parameters which have significant correlation with
RR revealed that age, preoperative morbidity period and DR were
associated with RR (p \ 0.001, R2 = 0.21).
Conclusions: Recently, preservation of ROM of cervical spine after
ELAP has been preferred to prevent development of postoperative
axial pain and to minimize ADL disturbance. However, results of this
study suggest that mobility of cervical spine could impair postoper-
ative neurological recovery. It has been reported in several literatures
that the degree of diminution of ROM after ELAP depended on the
period and the mode of postoperative external immobilization.
Therefore, the importance of the postoperative external immobiliza-
tion should be reconsidered to obtain the maximum postoperative
neurological recovery.
GROWING SPINE DEFORMITIES
P97
CORRELATION ANALYSIS BETWEEN DIGITAL
PHOTOGRAPHY MEASUREMENT OF TRUNK
DEFORMITY AND SELF-IMAGE PERCEPTION
IN PATIENTS WITH IDIOPATHIC SCOLIOSIS
Antonia Matamalas, Elisabetta D0Agata, Ferran Pellise, Juan Bago,
Enric Caceres
Orthopaedic Surgery, Barcelona, Spain
Introduction: It has been suggested that some measures of trunk
deformity obtained in digital photography can be useful in the
assessment of trunk deformity. The relationship between these mea-
sures and patients’ self-image perception has not been established.
Study design: Concurrent validity between postural indexes obtained
from digital photographs and self-assessed appearance questionnaires.
Objective: To assess the validity of a clinical assessment tool of the
trunk deformity based on photographs as compared to self-assessed
appearance questionnaires.
Methods: Front and back digital photographs of patients with idio-
pathic scoliosis (Cobb angle [ 258) were obtained. Shoulder, armpit
and waist angles in addition to trunk asymmetry indices were cal-
culated on front and back photographs with Surgimap software. All
patients completed SRS-22, SAQ, QLSDP and TAPS questionnaires.
The Pearson correlation coefficients (r) were used to estimate con-
current validity between both methods.
Results: 80 consecutive patients (68 females and 12 males) aged 12 to
40 years old (average 20.3 years old) were included. Mean Cobb
angle was 45.98 (range 25.18 to 77.28).A significant correlation was found between waist height angle and
TAPS (r = -0.31 to -0.34); SAQ appearance subscale (r = 0.27 to
0.35) and SAQ total score (r = 0.25 to 0.29). No correlation between
TAPS, SAQ and other photography measurements was found. No
correlations between photographs and total SRS-22 score or its sub-
scales and QLSDP were found.
Conclusion: Waist height angle measured with digital photography is
moderately correlated with perceived trunk appearance. Trunk
asymmetry is poorly correlated with self-assessed appearance. Pic-
ture scales are better correlated with photographs than verbal rating
scales.
P98
THE NORTHERN IRELAND EXPERIENCE
WITH GROWTH RODS: IMPROVING
SIGNIFICANT SCOLIOSIS DEFORMITY
David Spence, Deirdre Fee, Eugene Verzin, Gregory McLorinan,
Alistair Hamiliton, Niall Eames
Trauma & Orthropaedics, Belfast, UK
Objectives: Growth rods are being used increasingly worldwide in
the treatment of scoliosis. We report the Northern Ireland experience,
with a series of 25 patients over 8 years, and the effectiveness of the
growth rods in improving deformity.
Methods: Between June 2004 and October 2012, a consecutive series
of 25 patients have had growth rods inserted and subsequently
lengthened. Notes and X-rays were reviewed with demographic data
and Cobb angles recorded.
Results: Of the 25 patients, 17 were male and 8 female with an
average age at time of surgery 6.6 years (range 2 - 12 years).
Nine patients had a single growing rod inserted with 6 requiring
conversion to dual rods. 15 patients had dual rods inserted primarily
and 1 patient underwent the VEPTR procedure.
The levels instrumented ranged from T2 - L5 with hooks used
superiorly in 12 cases and only screws in the remainder.
The average Cobb angle pre-op was 70� (range 40� - 108�). At initial
follow-up, the Cobb angle had reduced to 44� (range 26�- 74�). At last
review the average Cobb angle was 40� (range 19� - 66�).
On average 3.91 lengthening procedures per patient were carried out
(range 1 - 10).
Complications were two broken rods and one rod that cut out
requiring revision.
Conclusion: This case series showed that growth rods can dramati-
cally improve significant scoliosis deformity, and improvement is
maintained with consequent lengthening procedures. The majority of
improvement occurs at the initial lengthening procedure, with the
insertion of dual rods the preferred technique.
The data suggests that the use of growing rods in the immature spine
is a safe and effective method for improving and maintaining the
corrected Cobb angle, in the Northern Ireland population.
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S757
123
P99
THE NOTTINGHAM QUESTIONNAIRE, A NEW
TOOL TO ASSESS QUALITY OF LIFE
IN NEUROMUSCULAR SCOLIOSIS
Hoda Mohajer-Bastami, Ann Marriott, George Arealis, Bev Beeson,
Nasir A Quraishi, Hossein Mehdian
QMC, London, UK
Introduction: There is limited literature regarding the use of a ded-
icated questionnaire to assess the outcome of spinal deformity
correction in patients with neuromuscular scoliosis. A multidisci-
plinary steering group were instrumental in designing an outcome
questionnaire in our unit for use in patients with Cerebral Palsy (CP)
and Duchenne Muscular Dystrophy (DMD).
Purpose: The purpose of this study was to assess the quality of life
(QOL) in patients with neuromuscular scoliosis following spinal surgery
using the newly devised Nottingham Questionnaire for Neuromuscular
scoliosis (NQNMS) with particular reference to CP and DMD patients.
Methods: Our questionnaire was developed by the steering committee
and granted ethical approval. The parameters assessed include sitting
posture/balance, arm use, head control, breathing, chest infections, pain,
eating, drinking, reflux, mobility, transferring, washing, dressing, daily
living, skin integrity before and after surgery. All answers were given by
the carers, parents or patients. Statistical analysis was performed using
the SPSS 17 and statistical significance was set at p = 0.5
Results: Between 2001 and 2011, 20 patients with NMS were treated
with posterior segmental screw fixation - 10 with (CP) and 10 with
(DMD). A total of 17/20 (85 %) carers responded - 9/10 patients with
CP and 8/10 with DMD.
At final follow-up (mean f/u 6.4 years (range 2-10), the parameters
that improved in both groups were sitting posture (p = 0.01), eating
and drinking and reflux (p = 0.33).
With mobility and transferring, and washing and dressing, there was
no difference before or after the operation for both CP and DMD
patients (p = 1.00) and the same happened with arm use (CP
p = 0.75, DMD p = 0.81).
Head control (p = 0.41) and breathing (DMD p = 0.28, CP
p = 0.62), improved in DMD patients only whilst pain improved in
CP patients (p = 0.17).
Post-operatively, there was 1 patient with superficial wound infection.
Conclusion: Our questionnaire is simple and easy to use for the
assessment of QOL in CP and DMD patients and had a good response
rate (85 %). Our study shows that spinal stabilization does improve
QOL through improvements in sitting posture, breathing, reflux,
mobility and transfer, washing, dressing and arm use. Validation of
the questionnaire in a larger group of patients is under way.
P100
IT IS POSSIBLE TO SPACE OUT THE TIME
BETWEEN GROWING RODS LENGTHENINGS
IN PATIENTS WITH JUVENILE SCOLIOSIS
AND STILL OBTAIN LONGITUDINAL CHEST
GROWTH
Javier Pizones, Tamara Rodrıguez, Patricia Alvarez-Gonzalez,
Lorenzo Zuniga, Felisa Sanchez-Mariscal, Enrique Izquierdo
Spine Unit. Orthopaedic Surgery. Hospital Universitario de Getafe,
Madrid, Spain
Introduction: Serial lengthening is recommended every six months
for the treatment of early onset scoliosis with growing rods. The
objective is to evaluate the longitudinal growth of the thorax and the
deformity control if the time between lengthening is spaced out, in a
series of patients with juvenile scoliosis.
Materials and methods: Retrospective study of eight patients with
juvenile scoliosis treated with growing rods whose lengthenings were
spaced more than six months apart. During the follow-up we mea-
sured: the Cobb angle, the apical vertebra traslation, the coronal
balance, the thoracic T1-L1 length, the thoracic T5-T12 kyphosis, the
proximal junctional kyphosis (PJK) angle, and the lumbar lordosis.
Complications were collected.
Results: Five idiopathic and three syndromic scoliosis. All had Risser
0 sign and open triradiate cartilage. Mean age 9.4 ± 1.5 years. Mean
follow-up of 78 months. Number of levels fused 12.4 ± 3.1. Mean
time between distractions 15.7 months, with an average of two dis-
tractions per patient. Four definitive fusions.
-Preoperative Cobb 56.5�, postoperative 24.75�, and final 23.75�(58 % correction). 16.8� were lost before the first lengthening and
11.5� before the second.
-Preoperative apical translation 4.8 cm and final 1.9 cm.
-Preoperative coronal balance 1.7 cm and final 1 cm.
-The thoracic (T1-L1) preoperative length was 20.8 cm, postoperative
24.3 cm, and final 26 cm. The initial surgery got to stretch 3.5 cm, the
first lengthening 3 cm and the second 2.6 cm, losing an average of
1.5 cm between elongations. At the end, the thorax’s average growth
was 5.2 cm.
-The preoperative (T5-T12) kyphosis was 33.5�, postoperative 23.4�,
and final 32�. 108 were corrected in the first surgery, 5.3� in the
second and 48 in the third surgery. An average of 6.4� were corrected
with each lengthening, losing an average of 5� between elongations.
-The change in PJK angle was 2.5� at final follow-up.
Conclusions: Spacing out lengthenings more than a year, in juvenile
scoliosis patients treated with growing rods, can spare surgeries while
still controlling the deformity and allowing longitudinal thoracic
growth.
P101
DOES INTRAOPERATIVE CELL SALVAGE
SYSTEM EFFECTIVELY DECREASE THE NEED
FOR ALLOGENEIC TRANSFUSIONS
IN SCOLIOTIC PATIENTS UNDERGOING
POSTERIOR SPINAL FUSION: A PROSPECTIVE
RANDOMIZED STUDY
Jianxiong Shen, Jinqian Liang, Sooyong Chua
Department of Orthopedic Surgery, Peking Union Medical College
Hospital, Beijing, China
Objective: To evaluate the safety and efficacy of intraoperative cell
salvage system in decreasing the need for allogeneic transfusions in a
cohort of scoliosis patients undergoing primary posterior spinal fusion
with segmental spinal instrumentation.
Background: Scoliosis patients undergoing posterior spinal fusion
can experience significant intraoperative blood loss and often require
perioperative blood transfusions. Cell saver can possibly obviate the
need for additional predonated autologous or allogeneic red blood cell
transfusion. However, there is conflicting evidence in the literature
regarding cell salvage system usage in pediatric orthopedic surgery.
Methods: A total of 92 consecutive scoliosis patients undergoing
posterior instrumented spinal fusion were randomized into 2 groups
S758 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
according to whether a Cell Saver machine for intra-operative blood
salvage was used or not. Data included age, body mass index, perioper-
ative hemoglobin levels, surgical time, levels fused, perioperative
estimated blood loss, perioperative transfusions and incidence of trans-
fusion related complications. A Chi square test and t tests were performed
for intraoperative and perioperative allogeneic transfusion between
groups. A regression analysis was performed between selected covariates
to investigate the predictive factors of perioperative transfusion.
Results: Perioperative allogenic blood transfusion rate were lower in
the cell saver group (10 % vs. 28.6 %, P = 0.022). Mean intraoper-
ative red blood cell transfusion requirement were also lower (0.16
U/pt vs. 0.52 U/pt, P = 0.041). The mean Hb and hematocrit levels in
the cell saver group were significantly higher in the first three days
(P \ 0.05). No marked differences were observed in transfusion
related complications between both groups (p = 0.292). A multi-
variate analysis demonstrated that preoperative hemoglobin value
(OR: 0.849; p = 0.008), surgical time (OR: 1.041; p = 0.019),
intraoperative estimated blood loss (OR: 1.011; p = 0.001) and the
use of cell saver system (OR: 0.007; p = 0.003) had a trend toward
significance in predicting likelihood of transfusion.
Conclusions: Cell saver use significantly reduces the need for allo-
geneic blood in spine deformity surgery, particularly in patients with
low preoperative hemoglobin or longer operation time. This study
confirms the utility of routine cell saver use during PSF with seg-
mental spinal instrumentation for scoliosis patients.
P102
PREOPERATIVE SKULL-FEMORAL TRACTION
WITH POSTERIOR VERTEBRAL COLUMN
RESECTION (PVCR) TO TREAT SEVERE RIGID
SPINAL DEFORMITY WITH ANGULAR
CURVES [ 150�
Jingming Xie, Zhi Zhao, Tao Li, Yingsong Wang, Ying Zhang, Ni Bi
Department of Orthopaedics, Kunming, China
Summary: To explore the significance of preoperative skull-femoral
traction in severe rigid spinal deformity with angular curves [ 150�.
Introduction: Based on the angulation, rotation of the spinal cord, the
extremely severe rigid spinal deformity with angular curves can be
effectively corrected by PVCR, but the high risk of it has also been
reached a consensus in the world. If the curves can be improved preop-
eratively, the safeties of PVCR and the spinal cord will be increased.
Methods: From 2004 * 2012, 98 consecutive cases with severe
spinal deformity were successfully treated by PVCR in authors’
institution, in which, 12 cases with extremely severe rigid deformities
and angular curves were treated by skull-femoral traction before
PVCR. For the 12 cases, the average preoperative major scoliosis
curve and kyphosis was 153�(110�-168�) and 109�(61�-180�). The
continuous skull-femoral traction in the supine position was started
from preoperative 4 weeks. In the process of traction, the tolerance
(diet, sleeping, pain, etc.), neurologic status, deformity changes, etc.
were documented for analysis. The surgical correction through PVCR
was performed at the end of the post-traction 4th week.
Results: For the 12 cases, the final traction force was 63 % of body
weight (47 %-75 %). After 4 weeks traction, the deformity was
improved both on coronal and sagittal planes (F = 64.196,
P = 0.000): the major scoliosis curve and kyphosis were decreased
34 % and 31 %. At the end of the 1st week, the major scoliosis curve
and kyphosis were decreased 19 % and 15 %. In the 2nd week, the
major scoliosis curve was decreased 11 % (Fig. 1), but kyphosis was
unexpected increased 4 %. The deformities improvement in the last
2 weeks was less obvious than the first 2 weeks (P = 0.000). After
PVCR, the major scoliosis curve and kyphosis were improved 69 %
and 66 %. No spinal cord injury occurrence.
Conclusions: Preoperative skull-femoral traction is effective to decrease
the risks of spinal cord displacement in PVCR. Along with the traction,
the scoliosis can be improved more obviously and much earlier than
kyphosis. Following the traction force exceeding 63 % of the body
weight, the tolerance of the patients will be obviously decreased. In the
process of traction, the rigid deformity is rotated from coronal to sagittal
planes so as to decrease the risks and difficulties of PVCR.
P103
NON-SEGMENTAL LOW IMPLANT DENSITY
PEDICLE SCREW CONSTRUCT IN LENKE TYPE 1
AND 2 ADOLESCENT IDIOPATHIC SCOLIOSIS-
DOES IT HAVE AN IMPACT ON DEGREE OF CURVE
CORRECTION AND THORACIC KYPHOSIS?
Renjit Krishnakumar
Orthopaedics, Cochin, Kerala, India
Study Design: Retrospective cohort study of 36 consecutive patients
with Lenke I an 2adolescent idiopathic scoliosis, at a single centre,
using all posterior non-segmental pedicle screw instrumentation.
Objective: To evaluate the coronal and sagittal correction of main
thoracic adolescent idiopathic scoliosis using all-pedicle screw non
segmental instrumentation with low implant density in.
Summary of Background Data: There is an increasing trend in the
use of bilateral segmental pedicle screw construct in scoliosis cor-
rection surgery which increases the implant load, decreases thoracic
kyphosis and increases the cost of surgery.
Methods: Thirty seven consecutive patients with Lenke 1 and 2
adolescent idiopathic scoliosis curve pattern underwent single stage
posterior correction and instrumented spinal fusion with non seg-
mental pedicle screw fixation between 2004 and 2011. Pre- and
postoperative radiographs were analyzed. Mean patient age at the
time of operation was 15 years.
Results: Minimum follow-up was 2 years. The mean preoperative
thoracic curve was 58.80 degrees and 14.8 degrees at final follow-up,
resulting in a mean correction of 74.7 % (p \ 0.001) The preopera-
tive thoracic kyphosis of 15.7 degrees increased to 23.1 degrees. The
mean screw density was 1.13.
Conclusion: Even with non segmental pedicle screw construct with
low implant density of 1.13 we could achieve 74 % of curve cor-
rection with improvement of thoracic kyphosis.
P104
SAGITTAL SPINO-PELVIC ALIGNMENT IN EARLY
THORACIC VERSUS EARLY (THORACO)LUMBAR
ADOLESCENT IDIOPATHIC SCOLIOSIS
Tom Schlosser, Suken Shah, Samantha Reichard, Kenneth Rogers,
Koen Vincken, Rene Castelein
Orthopedic Surgery, Utrecht, Netherlands
Background: Rotational stiffness of spinal segments is decreased by
posteriorly directed shear loads. Posterior shear loads act on
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S759
123
backwardly inclined segments of the spine as determined by the indi-
vidual’s inherited sagittal profile. Accordingly, it can be inferred that: (1)
certain sagittal spinal profiles are more prone to develop a rotational
deformity that may lead to idiopathic scoliosis; (2) lumbar scoliosis
develops on a different sagittal spinal profile than thoracic scoliosis.
Purpose: To compare the sagittal alignment and vertebral inclination
of early thoracic versus early (thoraco)lumbar scoliosis versus con-
trols in a systematic and reproducible way, and to examine the role of
sagittal alignment in the etiology of different types of idiopathic
scoliosis.
Design: Multicenter, cross-sectional study.
Methods: Standardized lateral radiograph of the spine of adolescent
idiopathic scoliosis patients with thoracic (n = 128) and lumbar
(n = 64) curves with a Cobb’s angle less than twenty degrees were
studied. Subjects who underwent scoliosis screening and had a normal
spine were included in the control cohort (n = 95). A systematic,
semi-automatic measurement of nine sagittal spino-pelvic parameters,
parameters describing the backwardly inclined segment and inclina-
tion of each individual vertebra between C7 and L5 was performed
for each subject using in-house developed computer software.
Results: Thoracic kyphosis was significantly smaller in thoracic
scoliosis than in lumbar scoliosis or controls. For thoracic scoliosis, a
significantly longer backwardly inclined segment and steeper back-
ward inclination of C7-T8 was observed compared to both lumbar
scoliosis and controls (Figure 1). In lumbar scoliosis, the backwardly
inclined segment was shorter and located lower in the spine, and T12-
L4 was more backwardly inclined than in the thoracic group. Lumbar
lordosis, pelvic tilt and incidence and sacral slope were similar for the
two scoliotic subgroups as well as controls.
Conclusions: This study demonstrates that the sagittal profile already
at an early stage of development of thoracic adolescent idiopathic
scoliosis differs significantly from lumbar scoliosis and controls. This
supports the theory that differences in sagittal profile play a role in the
development of different types of idiopathic scoliosis.
P105
IS THE KYPHECTOMY
FOR MYELOMENINGOCELE BENEFICIAL?
Yukitaka Nagamoto, Hidekazu Tobimatsu, Hiroyuki Aono,
Yukari Imajima, Motohiro Kitano
Orthopaedics, Osaka, Japan
Introduction: Severe kyphosis of myelomeningocele is a complex
disorder that usually requires kyphectomy. Although surgical correction
offers the possibility of restoring spinal alignment, kyphectomy is tech-
nically demanding and many complications can occur as result of the
surgery. Given the aforementioned facts, we wondered if the patents and
parents are really satisfied with the result of kyphectomy. The purpose of
our study is first to investigate our surgical results and perioperative
complication rates and second to elucidate patient and parent satisfaction
of kyphectomy for myelomeningocele.
Materials and methods: We reviewed 6 patients (3 male and 3
female) with myelomeningocele who had kyphectomy. The median
age at surgery was 9.5 years (4-19) and the median follow-up period
was 5.5 years (1-9.5). Outcome measures include radiographic mea-
surement (kyphotic angle and sacral slope), complication, and patient
and parent satisfaction. The patient and parent satisfaction was
assessed by mailing an original satisfaction questionnaire.
Results: In our case series, 3 were short fusions using plate and 3
were long fusions using spinal instrument. On an average, 2.7 (1-4)
vertebrae were resected. The mean kyphotic angle was 132�
preoperatively, 56� postoperatively, and 66� at the final follow-up. The
mean sacral slope was -38� preoperatively, -13� postoperatively, and -6�at the final follow-up. We identified 8 postoperative complications
including recurrence of kyphosis at adjacent segment, protruding hard-
ware, deep infection due to postoperative cast ulceration, and spinal fluid
leakage. Due to these complications, 22 additional surgeries were needed
in 3 of 6 patients. As for the satisfaction, 5 of 6 patients were answered
‘‘satisfied’’ including ‘‘satisfied a little’’ despite these all complications.
Especially, all patients were satisfied with the improvement of sitting
balance and prominent deformity in the low back.
Discussion: In previous studies, the percentage correction ranges
from 37 % to 96 % and complication rate remains greater than 50 %.
In our results, the percentage correction and complication rate were
50 % and 66 %, respectively and the results were equivalent as
compared with previous studies. Despite these all complications,
almost all patients and parents were satisfied with surgical results.
Given the results, it is very important to give fully informed consent
including all assumed risks and benefits before surgery.
P106
BRACE TREATMENT VERSUS OBSERVATION
ALONE FOR SCOLIOSIS ASSOCIATED
WITH CHIARI I MALFORMATION FOLLOWING
POSTERIOR FOSSA DECOMPRESSION: A CASE
CONTROL STUDY
ZHU Ze-zhang, SHA Shi-fu, SUN Xu, JIANG Long,
QIAN Bang-ping, QIU Yong
Spine Surgery, Nanjing, China
Objective: To investigate whether brace treatment subsequent to
posterior fossa decompression (PFD) produces better outcomes than
observation alone for scoliosis secondary to Chiari I malformation.
Methods: The clinical and radiographic data of all CMS patients who
underwent PFD at our center between January 1998 and November 2010
were retrospectively reviewed. Following PFD, 21 patients refused
bracing due to psychological concerns and were treated with observation
alone (Ob group), whereas 33 patients who received brace treatment were
assigned into the braced (Br) group. Evolution of scoliosis was defined as
progression if Cobb angle of the primary curve increased[ 5�, in
comparison with that at brace initiation; otherwise it was considered
improvement (decreased[ 5�) or stabilization (varied within 5�).
Results: The initial primary curve magnitude in the Br and Ob groups
averaged 33.3� ± 6.6� and 32.5� ± 7.8�, respectively. Duration of fol-
low-up in the Br group averaged 70.3 ± 22.4 months and in the Ob
group 61.9 ± 27.3 months. By the final visit, progression of primary
curve [ 5� occurred in 10/33 (30 %) of braced patients and 13/21 (62 %)
of observed patients (P = 0.022). Overall, 8 (24 %) patients in the Br
group and 9 (43 %) in the Ob group underwent corrective surgery
(P = 0.151). When analysis was restricted to those who had reached
skeletal maturity or undergone spinal fusion surgery, decreased curve
progression and surgical rates were also observed in the braced group but
did not meet the criteria for statistical significance (P [ 0.05). Results of
the survival analysis, however, demonstrated a significantly increased
survival proportion in the braced group (0.63 versus 0.35, P = 0.014).
Conclusion: Compared with observation alone, bracing subsequent to
PFD indeed reduces the rates of curve progression and scoliosis
surgery in patients with Chiari malformation-associated scoliosis.
Nonetheless, children and their parents should be informed that almost a
third of brace-treated patients still resort to surgery ultimately.
Keywords: Chiari malformation, posterior fossa decompression,
brace treatment, observation.
S760 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
OTHERS
P107
OUTCOMES OF SACRECTOMY FOR PRIMARY
SACRAL TUMORS
Ana Marıa Morales Codina, Sonia Munoz Donat, Diego Valverde
Belda, Susanne Eschenbach, Rafael Aguirre Garcıa, Maria Jesus
Molina Aguilar, Juan Antonio Martın Benlloch
Orthopaedic and Traumatology Department, Valencia, Spain
Introduction: The sacrectomy is an uncommon procedure indicated
in primary sacral tumors. They are diagnosed in advanced stages,
making more difficult a complete resection. Sacrectomy is associated
with a high complication rate. However, in some tumors is the only
effective treatment.
Objectives: Analyze the functional outcomes, complications, rate of
recidive and mortality of patients who underwent sacrectomy for
primary sacral tumor.
Materials and methods: Retrospective study of patients who under-
went sacrectomy between 1997 and 2012 for primary sacral tumor.
Diagnosis, type of sacrectomy, reconstruction, complications, oper-
ating time, recidive and mortality were documented.
Results: 16 patients (9 males), mean age at surgery 46 years (range,
28-90 years) with a diagnosis of primary sacral tumor underwent en bloc
sacrectomy.
The mean follow-up was 7 years (range: 1 - 13 years).
Chordoma was the most common primary tumor (12 patients). Other diag-
nosis included 1 osteochondroma, 1 leiomyosarcoma and 1 ependymoma.
We performed 7 total sacrectomies and 9 subtotal sacrectomies (13
combined anterior and posterior approach and 3 a single posterior
approach).
Of total sacrectomies, 4 were stabilized with double-rod and single
iliac screw, 3 with single-rod and single iliac screw.
Of subtotal sacrectomies, 3 were stabilized with single-rod and single
iliac screw.
At the first postoperative month all patients had paresis of lower
extremities, gait disturbance and sphincter dysfunction. At the last
chek, all patients had improved motor activity and gait disturbance
but remains sphincter dysfunction.
2 of the lumbopelvic instrumentation failed, requiring surgical revisions.
3 patients had recurrences (2 in intralesional resections), 2 metastasis
and 3 deaths.
Overall survival was 84 % at 5 years.
Conclusions: Sacrectomy is an aggressive procedure with a high com-
plication rate. Although patient’s quality of life depends on the extent of
sacral root resection and the establishment of sacroiliac stability, sacrectomy
can be performed successfully in the treatment of primary sacral tumors.
P108
SURGICAL MANAGEMENT OF CHORDOMA
IN THE SPINE
Ana Marıa Morales Codina, Sonia Munoz Donat,
Diego Valverde Belda, Carles Martınez Perez, Rafael Aguirre Garcıa,
Marıa Jesus Molina Aguilar, Juan Antonio Martın Benlloch
Orthopaedic and Traumatolgy Department, Valencia, Spain
Introduction: Chordoma is a rare primary bone tumor accounting for
1-4 % of all primary bone neoplasms. It is a relatively slow-growing,
low-grade malignancy tumor. However, due to their invasive nature
and rate of recurrence, they are considered malignant.
En bloc resection with negative margins results in improved local
disease control and have reported prognostic role in local recurrence
and improved survival.
Objectives: To analyze the surgical treatment results of chordoma in
terms of complications, local recurrence, metastasis and mortality.
Materials and methods: Retrospective study of patients who
underwent surgical treatment between 1997 and 2012 for chordoma in
spine.
Inclusion criteria for the current study were patients with diagnosis of
chordoma without history of prior surgical or nonsurgical treatments
of the neoplasm. Patients were excluded from the study if they had
undergone prior radiation treatment and if they had prior surgery with
recurrent tumor requiring secondary salvage tumor excision.
Results: We analyzed 19 patients (12 men), mean age at surgery
48 years (range, 28-90 years).
The mean postoperative follow-up was 7 years (range: 1 - 13 years).
The location is 13 sacro-coccygeal, 4 lumbar, 1 thoracic, 1 cervical.
2 patients underwent intralesional resection and 17 patients was
performed en bloc resection of the tumor and surgical reconstruction
(12 patients).
2 of the cases had contaminated surgical margins.
In the early postoperative period (first month) 16 patients had motor
deficits in extremities and all had undergone a sacrectomy had
sphincter and sexual dysfunction. At the last visit extremity motor
deficit had improvement but remains sphincter dysfunction, for sacral
location.
2 of the lumbopelvic instrumentation failed, requiring surgical
revisions.
3 patients had recurrences (2 in intralesional resections), 1 metastasis
and 3 deaths.
Overall survival was 84.5 % at 5 years.
Conclusions: Despite the complications and consequences involved
en bloc resection of these tumors is the procedure of choice in the
treatment of chordomas because of its high survival rate and low
number of recurrences.
P109
INTER-TESTER AGREEMENT AND VALIDITY
OF IDENTIFYING LUMBAR PAIN PROVOCATIVE
MOVEMENT PATTERNS USING ACTIVE
AND PASSIVE ACCESSORY MOVEMENT TESTS
Benjamin Hidalgo, Toby Hall, Henri Nielens, Christine Detrembleur
Faculty of Motor Sciences, University of Louvain, Brussels, Belgium
Background and objectives: Clinical examination comprises pain
provocation tests including active trunk movements and passive
accessory intervertebral motion (PAIVM). These tests help to deter-
mine a pain provocative movement direction, which in turn helps
determine manual therapy management of low back pain (LBP). To
date there is little evidence regarding the inter-examiner agreement
and validity of this combined process. The purpose of this study was
to evaluate the inter-examiner agreement and validity of these com-
bined pain provocation tests.
Method: Two blinded raters examined 36 subjects, 18 of whom were
asymptomatic while 18 reported subacute non-specific LBP. Two
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S761
123
types of pain provocation tests were carried out: Physiological
movements in single (flexion/extension) and, when necessary, com-
bined planes; and PAIVMs of each lumbar spine vertebra in prone
with the lumbar spine in neutral, flexion, and extension position.
Inter-observer agreement was assessed by percentage of agreement,
as well as Kappa and prevalence adjusted bias adjusted Kappa (PA-
BAK). Validity was determined by comparing findings in
asymptomatic subjects to those with LBP.
Results: The inter-observer agreement in both populations was good
to excellent for the identification of flexion [K = 0.87 - 1] or
extension [K = 0.65 - 0.74] as the most painful pattern of spinal
movement. In healthy subjects 0 % were identified as having a flexion
provocative pattern and 8.8 % were identified as having an extension
provocative pattern. In the LBP group, 20 % were identified as having
a flexion provocative pattern versus 60 % with an extension pro-
vocative pattern. The average inter-examiner agreement for PAIVMs
in both groups was moderate to excellent [K = 0.42 - 0.83]. The
lower lumbar vertebrae showed a significant (p \ 0.001) higher
prevalence of positive pain responses to PAIVMs than the upper
lumbar vertebrae. The examiners showed good sensitivity [0.67 -
0.87] and specificity [0.82 - 0.85] to distinguish subjects with LBP
using this combined examination procedures.
Conclusions: The use of a combination of pain provocative tests was
found to have acceptable inter-examiner reliability and good validity to
identify the main pain provocative movement pattern and the lumbar
segmental level of involvement. These tests can be used with confidence
by clinician’s to aid in the manual therapy management of LBP.
P110
DIFFUSION-WEIGHTED MAGNETIC RESONANCE
(DW-MR) NEUROGRAPHY OF THE LUMBAR
PLEXUS IN THE PREOPERATIVE PLANNING
OF LATERAL ACCESS LUMBAR SURGERY
Cristiano Menezes, Luciene Andrade, Marcello Nogueira-Barbosa,
Carlos Fernando Herrero, Helton Defino, Willian Blake-Rodgers
Spine Surgery - Lifecenter Hospital, BELO HORIZONTE, Brazil
Introduction: Lateral access lumbar surgery has rapidly increased in
popularity in the last several years. However, the technique remains
limited by the risk of injury to the lumbar plexus, most commonly the
femoral nerve near the L4L5 level. While real-time neural monitoring
can decrease the incidence of such injuries, postoperative deficits can
still occur. Magnetic resonance (MR) neurography has been used to
evaluate abnormal conditions of entire nerves and nerve bundles by
providing better contrast between the nerves and the surrounding
tissues. The purpose of this study is to introduce and assess DW-MR
neurography for imaging of the lumbar plexus in the preoperative
planning of lateral access surgery. By providing the surgeon with a
preoperative roadmap of the lumbar plexus, DW-MR may improve
the safety profile of lateral access procedures.
Methods: Sixty patients (120 sides) with degenerative spine disorders
and history of low back pain underwent a DW-MR examination of the
lumbar plexus in relation to the L3L4 and L4L5 disc spaces and
superior third of the L5 vertebral body. Images were reconstructed in
axial plane using high-resolution 10 mm MIP slabs over the disc
space and 22 mm MIP slabs in L3-L4 and L4-L5 interspace to mimic
the working zone of standard lateral access retractors. L4 spinal nerve
and femoral nerve position were analyzed relative to the L4L5 disc
and this position was confirmed in sagittal planes.
Results: In all subjects the plexus was successfully mapped. At L3L4,
all components of the plexus (except the genitofemoral nerve) were in
zone 4. The L3 and L4 roots coalesced into the femoral nerve below
the L4L5 disc space in all subjects. Side to side variation was noted,
with 51 (84.7 %) of plexa in zone 4 on the right vs 44 (72.9 %) on the
left. At the superior third of L5, the plexus was found in zone 3 in 13
(22 %) and 24 (33.9 %), respectively; and at zone 2 in 3 (5.1 %) on
the right and 2 (3.3 %) on the left.
Conclusion: DW-MR neurography appears to afford a noninvasive
method of mapping the lumbar plexus preoperatively.
P111
NEUROPHYSIOLOGIC APPROACH
FOR INTRAOPERATIVE IDENTIFICATION
OF THE INJURY LEVEL AFTER SPINAL CORD
DAMAGE DURING SPINE SURGERY. A NEW
METHOD EXPERIMENTALLY TESTED IN PIGS
Jesus Burgos, Gema de Blas, Lidia Cabanes, Javier Cervera,
Eduardo Hevia, Carlos Barrios, Carlos Correa
Institute for Research on Musculoskeletal Disorders, Valencia
Catholic University, Valencia, Spain
Introduction: Intraoperative spinal cord injury is a complication that
may have important clinical consequences. In most instances, the
intraoperative identification of the injury level might allow immediate
spinal decompression, increasing the chance for later recovery. This
study presents a new neurophysiologic method that was experimen-
tally tested in a pig model.
Materials and methods: Five industrial pigs were included in the
experiment. Bilateral laminectomies were performed to expose the
spinal cord at T4-T5, T7-T9 and T12-T13 segments. Pedicle screws
were inserted left at T5, T7, T9 and T12. Four epidural catheters were
placed sublaminar for neurophysiologic recording in T3, T6, T11 and
L1. The neurophysiologic techniques performed were: a) cord-to-cord
motor spinal-evoked potentials between the epidural catheters; b)
recording of the sensory epidural potential after stimulation of a
mixed nerve of the lower limb; c) recording of the motor D-wave in
the epidural catheters after transcranial stimulation; d) Pulse-train
stimulation of the four screws and recording of the responses in
epidural catheters. After basal recording, the spinal cord was sec-
tioned with a scalpel at T8 pedicle level and the neurophysiologic
study was repeated for determining the level of injury.
Results: In all cases, there was a lack of caudal cord-to-cord motor
potential when the spinal cord was stimulated just above the section.
The epidural sensory potentials were normal in the two levels caudal
to the medullary section and absent in the two segments craneal to the
section. The motor D-wave was completely normal at the levels
above the injury, and absent int the two caudal segments. Pulse-train
stimulation of the screws craneal to the spinal cord section showed
caudal response in the distal epidural catheters in three cases.
Conclusions: It is feasible to identify intraoperatively the level of
an spinal cord injury by neurophysiologic methods. Cord-to-cord
stimulation techniques, epidural sensory evoked potentials and
the D-wave recorded at various levels permit to identify the
exact location of the spinal cord injury. The pulse-train screw
stimulation technique is less accurate in identifying the level of
injury.
S762 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
P112
IDENTIFICATION OF OBSTACLES
TO RECOVERY IN SECONDARY CARE
Kwang Chear Lee, Shakil Patel, Philip Sell
Orthopaedics, Leicester, UK
Introduction: Yellow flags are psychosocial indicators which are
associated with a greater likelihood of progression to persistent pain
and disability. The yellow flags are referred to as obstacles to
recovery. It is not known how effective clinicians are in detecting
them. Our objective was to determine if clinicians were able to detect
them in secondary care.
Methods: 88 new referrals in a specialist spine clinic completed the
Oswestry Disability Index and a range of other validated question-
naires including the yellow flag questionnaire adapted from the
psychosocial flags framework. Clinicians blinded to the patient data
completed a standardized form to determine which and how many
yellow flags they had identified.
Results: The average number of yellow flags per patient was 4.8
(range: 0-9). Clinician sensitivity in detecting yellow flags was poor,
identifying on average only 41 % of flags. The most common yellow
flag reported by patients was fear of movement or injury (n = 78) and
this was correctly reported by clinicians in 39 patients. Patient cata-
strophising (‘‘Do you think pain is terrible and will never get better?’’)
was most frequently missed by clinicians (n = 41) and the most com-
monly misidentified was the lack of coping strategies and patient
uncertainty (both n = 25). Patients who reported more yellow flags were
more likely to score higher on the modified somatic perception score
(Pearson correlation = 0.53, p \ 0.01) and had poorer Low Back Out-
come Scores (LBOS) (Pearson correlation = -0.461, p \ 0.01).
Conclusion: Clinician sensitivity in detecting yellow flags is poor.
Improved identification of obstacles to recovery may improve out-
comes. Clinicians may improve detection of these obstacles by having
a simple set of questions completed by the patient.
P113
THE USE OF CEMENT AUGMENTED SCREWS
IN LUMBAR SPINAL FUSION IN OSTEOPOROTIC
PATIENTS. DOES IT ADD ANY CLINICALLY
RELEVANT MORBIDITY?
Luis Alvarez, Angel R Pinera, Felix Tome, Belen Lopez San Roman,
Carmen Duran, Daniela Vlad, Ignacio Mahillo
Fundacion Jimenez Dıaz. Spine Unit, Madrid, Spain
Introduction: Pedicle screws encounter difficulty in achieving and
maintaining fixation in osteoporotic vertebrae, and have been shown
to loosen in these patients.. As a result, some spine surgeons may
refuse to perform instrumentation on osteoporotic patients with
lumbar instability. The use of cement to augment pedicle screw fix-
ation yields increased resistance to pullout and/or toggle failure in the
cephalad-caudad direction as reported in numerous studies. However
there is a concern in its used because associated potential morbidities.
In our knowledge, no clinical study has analyzed these potential
complications. The purpose of this study is to analyzed the possible
complications related with the cement augmented screws.
Materials and methods: This is a retrospective study including all
the patients treated in one Center with cement augmented screws
since November 2006 until November 2012. We include 225 patients,
with a mean age of 73.7 years old, and a mean follow-up of
31.8 months. Indication for fusion was degenerative disease in 168
cases, fracture in 37 cases, deformity in 18 cases and tumor in 2
patients. Leakages were classified as epidural, foraminal, intradiscal,
venous paravertebral, canal, and extravertebral on a post-operative
CT scans. Clinical charts were analysed for clinical complications,
including radicular pain related with cement leakages, infection,
extraction of screws and failure of the instrumentation.
Results: 598 vertebrae were instrumented with 1134 cemented
screws. Cement leakage was observed in 53.5 % of the vertebrae;
Four vertebra had a canal leakage, with no clinical relevance.
Radicular pain was observed only in 4 patients, all of them with a
foraminal leakage at S1. There were 20 patients (8 %) with a deep
infection that required surgical debridement. In none of these cases
removal of instrumentation was necessary. Thirty patients (13.3 %)
required a revision surgery. Twenty for the treatment of the adjacent
level and 10 pseudoarthrosis. None of the 103 screws removed a
extraction torque required was difficult. All pseudoarthosis were
found in long fusion constructs (more than 4 levels), and in 6 cases a
broken rod was observed.
Conclusion: This study demonstrates that the use of cement to aug-
ment pedicle screws is a safe procedure. Augmentation with cement
allows an excellent attachment of the screws, so in case of pseudo-
arthrosis there is a failure of the rod first.
P114
THE LOCAL APPLICATION OF VANCOMYCIN
FOR THE PREVENTION OF LUMBAR SPINE
WOUND INFECTION
Martin Komzak, Radek Hart, David Nahlık, Filip Buek,
Vojtch Prochazka
Department of Orthopaedics and Traumatology, Znojmo, Czech
Republic
Introduction: Postoperative spinal wound infections are relatively
common. They are associated with significant morbidity, increased
costs, and poor long-term outcomes. As the use of spinal instru-
mentation has become common, infection rates in elective
instrumented cases as high as 3 % to 6 % have been reported. The
aim of this prospective study was to evaluate the incidence of surgical
site infection following elective instrumented lumbar spine operations
supplied with locally poured vancomycin.
Methods: Between September 2008 and September 2012, 200
patients (112 men, 88 women) in the mean age of 59 years (range, 30 to
87 years) were included in the study. In all cases, transpedicular screw
instrumentation (S4�, B/Braun-Aesculap, Tuttlingen, Germany) was
used. Other procedures were often added (fusion, decompression). In the
end of the surgery, vancomycin powder (vancomycin hydrochloride
0.5 g; Edicin�, Sandoz, Ljubljana, Slovenia) was poured into the wound.
Antibiotic prophylaxis was used in all patients consisting of 1 g of
intravenous cefazolin within 1 h before the operation and additional six
doses every 4 h. Incidence of risk factors was:
1) obesity (BMI C 26): 178 patients (89 %), mean value 29 (range,
21-43), median 28.5;
2) old age (C 70 years): 84 patients (42 %);
3) diabetes mellitus: 36 patients (18 %);
4) smoking: 36 patients (18 %);
5) cardiovascular disease: 122 patients (61 %);
6) bronchopulmonary disease: 30 patients (15 %);
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S763
123
7) malignancy: 8 patients (4 %);
8) steroid use: 6 patients (3 %).
Results: Postoperative wound infection didn0t occur in any case.
Aseptic haematoma developed in 4 cases and was treated with revi-
sion and drainage.
Discussion and conclusions: Despite the administration of prophy-
lactic antibiotics, surgical site infections are not uncommon following
lumbar spine operations. The additional local application of vanco-
mycin is the reliable measure for preventing this complication also in
cases at risk.
P115
INCOMPLETE CORRECTION OF SAGITTAL
SPINAL ALIGNMENT AFTER HIP FLEXION
CONTRACTURE TREATMENT WITH THR
Martin Komzak, Radek Hart, Martin Feranec, David Nahlık, Petr Mıd
Department of Orthopaedics and Traumatology, Znojmo, Czech
Republic
Introduction: It has become well recognised that sagittal balance of
the spine is the result of an interaction between the spine, the pelvis and
the hip. Flexion contracture is a frequent finding in patients with osteo-
arthrosis of the hip. Only few studies have insisted on the relationship
between spinopelvic parameters and hip flexion parameters.
Methods: A prospective study was carried out on 40 patients with
flexion contracture of the hip. The test of Thomas was used to identify
and measure (pre- and postoperatively) the deformity. The parameters
of pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS) and lumbar
lordosis (LL) were analysed on lateral standing radiographs of the
lumbosacral spine before and one year after the flexion contracture
release and the short stem total hip replacement (Metha, B/Braun-
Aesculap, Tuttlingen, Germany).
Results: The average value of the flexion contracture of the hip was
preoperatively 17� (range, 5� to 30�) and postoperatively 4� (range, 0�to 10�) (p = 0.018). PI didn0t change after the surgery (as expected)
with a mean value of 57� (range, 37� - 72�). Compensatory balance
parameters (PT, SS) changed postoperatively in all but one case.
Preoperative and postoperative average value was for PT 14� (range,
1� to 30�) and 18� (range, 3� to 32�), respectively (p = 0.25); for SS
43� (range, 26� - 56�) and 39� (range, 23� - 54�), respectively
(p = 0.31). LL changed less than 1� at average.
Discussion and Conclusions: This is one of the first series analysing
the hip flexion contracture as a cause of sagittal spinal imbalance. The
compensatory pelvic parameters (PT, SS) of the spine balance adjust
postoperatively after hip joint flexion reduction at one year follow-up,
but not significantly.
P116
POSSIBILITIES OF SEQUELAE SPINAL CORD
INJURY TREATMENT
Nataliia Sych
Cell Therapy Center EmCell, Kiev, Ukraine
Goal: study clinical efficacy in patients with sequelae of spinal cord
injury (SSCI) treatment under the influence of fetal stem cells (FSC)
treatment.
Materials and methods: The paper contains the results analysis of 23
patients with consequences of SSCI, 15 man, 8 women, with the age
range between 25 to 60 years old. Duration of injury to an average of
4.2 ± 0.34 years. The 9 patients had an injury of the cervical spine in
14 patients - the thoracic spine. All patients had a spinal injury was
confirmed by magnetic resonance imaging. All patients underwent
clinical, neurological research, assessment of the scale, the assess-
ment of quality of life on a scale of SF-36. Patients with SSCI were
timely monitored at 0, 1, 3 months after the stem cell transplantations.
Patients underwent transplantation of fetal hematopoietic and non-
hematopoietic mesenchymal and ectodermal stem cells harvested
from germ layers of internal organs of 5-8 weeks old legally aborted
fetuses and routine therapy.
Results: According to the scale independence spinal 34.78 % of patients
showed improvement in the area of ‘‘control sphincter’’ at 1 month after
treatment with FSC and 52.17 % of patients after 3 months after treat-
ment with FSC. Marked improvement in gait and 26.08 % of patients at
1 month after treatment with FSC and 47.82 % of patients after
3 months. In 17 patients with trauma were identified pressure ulcers in the
sacral region. 1 month after treatment, six patients had a decrease in
diameter and pressure ulcers in 11 patients at 3 months after treatment,
we observed FSC also reduce pressure ulcers in diameter, two patients
healed pressure ulcers. Analysis of the results according to the scale of the
SF-36 showed that in patients with SSCI with improvements in the fol-
lowing subtests 1 month after treatment FSC: of physical functioning,
mental health, and emotional role functioning, vitality and social role
functioning, but the degree of reliability achieved no, p [ 0.05. 3 months
after FSC therapy, significant improvement was reported in the emotional
role functioning, social role functioning, p \ 0.05.
Conclusions: The results indicate a significant clinical efficacy of this
variant cell therapy in patients with a history of SSCI. The use of
cellular technology in the treatment of patients with SSCI demon-
strated its significance and perspective.
P117
DOES SPINAL CORD DECOMPRESSION REDUCE
SPASTICITY IN PATIENTS WITH SPINAL CORD
INJURY AND RESIDUAL COMPRESSION?
Ratko Yurac, Sergio Ramırez, Sergio Mandiola, Miguel Lecaros,
Juan Zamorano, Carlos Tapia, Francisco Ilabaca, Alejandro Urzua,
Jose Fleiderman
Traumatologia, Santiago, Chile
Introduction: Spasticity, a disorder resulting from a superior moto-
neuron injury, is characterized by involuntary muscle activation, both
intermittent and sustained, which can be very bothersome for some
patients. It can affect up to 70 % of spinal cord injury (SCI) patients
and may appear months or years after the acute injury. While selec-
tive posterior rhizotomy is the main surgical procedure used to reduce
spasticity; orthopaedic procedures, such as tenotomies, myotomies,
tendon transpositions and elongations are used to correct deformities,
prevent muscular contractions and bone complications in patients
with advanced spasticity. Other procedures like myelotomies present
good results in selected patients that have no chance of recovering
voluntary motor function.
We have observed that some SCI patients evolve with progressive
spasticity, resistant to pharmacological treatment, due to residual
spinal cord compression. The objective of this study is to describe the
clinical results of surgical spinal cord decompression for the treatment
of refractory spasticity in this type of patients.
S764 Eur Spine J (2013) 22 (Suppl 5):S720–S766
123
Materials and Methods: We reviewed our institution’s database of
patients with traumatic SCI treated between 1992 and 2009 (196
patients), identifying three patients who evolved with spasticity
resistant to pharmacological treatment. They were studied with CT
and MRI, revealing focal spinal cord compression due to bone spurs.
Surgical decompression through a posterior approach was performed
in all three patients. Baseline and post surgery modified Ashworth
scale and drug requirements were used to assess the intervention’s
effect on their spasticity.
Results: Three patients with ASIA A SCI (two thoracic and one
thoracolumbar injury, mean age at the time of decompressive surgery
40 years) and Ashworth grade 3 spasticity in spite of maximum doses
of baclofen in two of them. The three patients presented a reduction of
their spasticity after the procedure (two to grade 1 and one to grade 2),
allowing all of them to discontinue pregabalin and even benzodi-
azepines in one patient. Baclofen doses remained unchanged.
Conclusion: In our experience, spinal cord decompression surgery
presents good results in patients with a previous traumatic SCI and
refractory spasticity in the context of spinal cord compression due to
bone spurs. This procedure should be considered as a less aggressive
alternative to cord surgeries in these patients.
P118
THE EFFECT OF PSYCHOLOGICAL STATUS
ON POSTOPERATIVE SATISFACTION
AND CLINICAL OUTCOMES IN SPINAL SURGERY
PATIENTS
Wan-Sik Seo, Sang-Hyun Lee, Hong-Sik Kim, Seung-Wook Baek,
Ye-Soo Park
Orthopaedic Surgery, Guri city, Korea (ROK/South Korea)
Purpose: The purpose was to evaluate the effect of psychological
status on postoperative satisfaction and clinical outcomes of patients
who received surgical treatment for degenerative spine disease.
Methods: Among patients who received short segment spinal fusion
in two or less segments for degenerative spine disease between Jan-
uary 2007 and February 2010, 206 patients for whom follow-up
observation was possible for at least 2 years were selected as subjects.
Psychological status of subjects before surgery such as depression,
anxiety and optimism were evaluated using Hospital Anxiety and
Depression Scale(HADS) and Revised Life Orientation Test(LOT-R).
Clinical evaluation was performed by measuring the degree of
improvement according to changes in Visual Analogue Scale(VAS)
and Oswestry Disability Index(ODI) before and after surgery. Their
correlation was evaluated, and satisfaction of subjects after surgery
was comparatively analyzed with psychological status before surgery
after dividing subjects into satisfied group and dissatisfied group.
Results: VAS and ODI showed statistically significant reduction after
surgery (P \ 0.0001), suggesting a clinically satisfactory outcome. In the
correlation analysis on psychological status and clinical outcomes,
optimism showed positive correlation (P\ 0.0001) with improvement in
ODI after surgery. Anxiety and depression showed negative correlation
(P \ 0.0001) with improvement in ODI after surgery. However,
improvement in VAS after surgery did not show significant correlation
with optimism, anxiety and depression before surgery. In comparison of
satisfaction among groups, satisfied group had significantly higher value
for optimism (P \ 0.0001) and significantly lower values for anxiety and
depression(P\ 0.0001, 0.0058) compared to dissatisfied group.
Conclusion: Psychological status of patients according to anxiety,
depression and optimism before surgery was found to be related with
the degree of improvement in Oswestry Disability in terms of satis-
faction and clinical outcomes after surgery. Accordingly, in order to
increase clinical outcomes and satisfaction of patients, careful eval-
uation and proper management of psychological status before surgery
are deemed necessary.
P119
RADIOGRAPHIC ANALYSIS OF SPINO-PELVIC
SAGITTAL ALIGNMENT IN CHINESE
ASYMPTOMATIC SUBJECTS
Weishi Li, Zhuoran Sun, Zhongqiang Chen
Orthopaedic Department of Peking University Third Hospital,
Beijing, China
Objective: To determine the physiological values of spinal-pelvic
sagittal parameters in asymptomatic Chinese adults, and to describe
the normal patterns of spinal-pelvic alignment in a Chinese
population.
Methods: This was a prospective radiological analysis. Whole spine,
standing lateral radiographs of 171 Chinese volunteers were taken.
The pelvic and spinal parameters (pelvic incidence, pelvic tilt, sacral
slope, lumbar lordosis, thoracic kyphosis, cervical lordosis, sagittal
vertical axis, apex of total lumbar lordosis, total lumbar lordosis,
upper arc of total lumbar lordosis, lower arc of total lumbar lordosis,
junctional level, apex of total thoracic kyphosis, total thoracic ky-
phosis, total cervical lordosis, lordosis tilt) were measured and the
correlations of all parameters were analyzed.
Results: Total of 171 volunteers were identified (94 males and 77
females), had a mean age of 23.0 years (18 to 28 years). The mean
value of pelvic incidence was 44.7 ± 9.5�, significantly less than that
reported in western subjects, even less than that reported in a Korean
population. Total lumbar lordosis has a significant correlation with
pelvic incidence, sacral slope, total thoracic kyphosis, cervical lor-
dosis and sagittal vertical axis. Apex of total lumbar lordosis showed
a significant correlation with pelvic incidence, sacral slope, junctional
level, lordosis tilt, sagittal vertical axis. The volunteers were classified
into four patterns according to their apex of total lumbar lordosis.
Conclusions: The pelvic sagittal morphology of Chinese adults was
significantly different from that of western and Korean. Lumbar lor-
dosis turned into a core in regulating spinal sagittal balance by pelvis.
As apex of total lumbar lordosis moved cranially, the lordosis tilt
decreased, whereas the lower lumbar lordosis, pelvic incidence, and
sacral slope increased .
Keywords: pelvic incidence, spinal-pelvic, sagittal alignment
P120
A NOVEL AUGMENTED REALITY ASSISTED
PERCUTANEOUS VERTEBROPLASTY
TECHNIQUE
Yuichiro Abe, Shigenobu Sato, Hiroyuki Yasuda
Eniwa Hospital, Eniwa, Japan
Augmented reality (AR) is an imaging technology for overlaying virtual
objects onto the images of real objects captured by a web-camera in real
time. We developed a novel AR guidance system for percutaneous
Eur Spine J (2013) 22 (Suppl 5):S720–S766 S765
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vertebroplasty, called Virtual Protractor with Augmented Reality
(VIPAR). The aim of this study was to introduce an AR guidance system
to visualize 3-dimensional needle trajectory in percutaneous verteb-
roplasty (PVP).
Methods: This AR system consists of a head mount display (HMD)
with a web-camera and AR software. AR software created the aug-
mented scene by overlaying the preoperatively generated needle
trajectory onto the detected marker on the patient surface, and pro-
vided the surgeon an augmented image through the HMD in real-time.
With looking the augmented needle trajectory, surgeon can insert the
needle into the fractured vertebra safely. Accuracy of the system was
evaluated using a computer generated simulation model in the spine
phantom. The error of inserted angle (EIA) was defined as the dif-
ference between attempted angle and inserted angle, was evaluated by
3D CT scans. Five patients with osteoporotic vertebral fracture
received PVP under the guidance of VIPAR from October 2011
to May 2012, and EIA was also evaluated using postoperative CT
scans.
Results: CT analysis of a total of 40 trials in the spine phantom
showed that EIA in the axial plane significantly improved from
4.34 ± 2.36 degrees in without guidance group to 0.96 ± 0.61
degrees in VIPAR group. EIA in the sagittal plane also significantly
improved from 2.55 ± 1.93 (w/o) to 0.61 ± 0.70 (VIPAR) degrees.
The clinical result of the five patients showed that EIA in all 10
needle insertions was 2.09 ± 1.3 degrees in the axial plane and
1.98 ± 1.8 degrees in the sagittal plane. There was no pedicle breach
or leakage of PMMA.
Conclusion: VIPAR demonstrated success in assisting needle inser-
tion in PVP as a virtual protractor by providing the surgeon an ideal
incision point and the needle trajectory through the HMD. AR
guidance technology could become a useful assistive device for spine
surgeries requiring percutaneous procedures.
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