126S Proceedings of the NASS 22nd Annual Meeting / The Spine Journal 7 (2007) 1S–163S

METHODS: A retrospective review of all patients who underwent a PSFI

down to L3 for double major AIS using lumbar pedicle screws was per-

formed at a single institution. Radiographic parameters were analyzed pre-

operatively, postoperatively and at 2 year follow-up. A good radiographic

outcome at 2 years was defined as: L3 less than 10 �, L3 translation less

than 25 mm, L3-4 disc angle less than 10 � and LAVT less than 30 mm.

Predictive factors leading to a good 2 year outcome were divided into

preoperative and intraoperative.

RESULTS: There were 41 patients, with an average age of 14.1 years, all

fused to L3. Preoperatively, the distal end vertebra was L3 in 20 patients

(L3 group) and L4 in 21 (L4 group). Preoperative Factors: When the pre-

operative end vertebra was L3, there were no preoperative predictors for

a good outcome. For the L4 group, the following preoperative parameters

predicted a good outcome: L3 tilt less than 15 �, lumbar apical vertebral

translation (LAVT) less than 34 mm, and a thoracolumbar curve (TL/L)

less than 52 � (p!0.05). Intraoperative Factors: For the L3 and L4 groups,

intraoperative TL/L curve correction (p!0.0006), L3 tilt % correction

(p!0.0007), and improvement in LAVT (p!0.0389) correlated with a good

outcome.

CONCLUSIONS: Determination of the preoperative end vertebra is im-

portant when performing a PSFI to L3 for double major AIS curves. When

the end vertebra is L3, successful outcome is dependent only on the intra-

operative deformity correction. When the end vertebra is L4, preoperative

assessment of L3 tilt, LAVT and the magnitude of the thoracolumbar

curve, and the amount of intraoperative deformity correction determine

success.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

doi: 10.1016/j.spinee.2007.07.300

P94. Anterior/Posterior Surgery for Cerebral Palsy Scoliosis: Staged

or Same Day?

Suken Shah, MD1, Paul Sponseller2, Mark Abel3, Peter Newton, MD4,

Daniel Sucato, MD5, Lynn Letko6, Randal Betz, MD7; 1Wilmington, DE,

USA; 2Johns Hopkins University, Baltimore, MD, USA; 3University of

Virginia, Charlottesville, VA, USA; 4San Diego, CA, USA; 5Dallas, TX,

USA; 6Klinikum Karlsbad-Langensteinbach, Karlsbad-Langensteinbach,

Karlsbad-Langensteinbach, Germany; 7Temple University, Philadelphia,

PA, USA

BACKGROUND CONTEXT: Although posterior surgery remains the

preferred approach for the treatment of scoliosis due to CP, occasionally

anterior and posterior (AP) surgery is performed for larger, rigid curves.

PURPOSE: The purpose was to define the utility and timing for anterior

surgery when a subsequent posterior procedure is planned for patients with

CP.

STUDY DESIGN/SETTING: A multicenter database of 157 children

with CP and scoliosis who underwent surgery with minimum 2-year follow

up was reviewed retrospectively.

PATIENT SAMPLE: Children with CP and scoliosis who underwent sur-

gery with minimum 2-year follow up. Forty-eight patients had anterior sur-

gery, 9 were staged on different days (STG) and 39 were done on the same

day (SD).

OUTCOME MEASURES: Radiographic parameters, OR/hospital data

and complications, preoperative risk assessment including cognition, feed-

ing method, verbal ability, ambulation, GMFCS scores were obtained for

each patient.

METHODS: Radiographic parameters, OR/hospital data and complica-

tions were compared between AP and posterior patients and STG and

SD patients using repeated measures ANOVA. Preoperative risk assess-

ment including cognition, feeding method, verbal ability, ambulation,

GMFCS scores and radiographic variables showed that the groups were

quite homogenous, i.e., the STG patients were not necessarily ‘‘sicker.’’

RESULTS: The length of stay was 9 days for the SD group and 46 days

for the STG group (p50.001). EBL was 1617 cc for SD versus 3428 cc for

STG (p50.001). OR time was 484 min for SD versus 524 min for STG

(p50.2). Overall complications were not significantly different based on

the timing of anterior surgery. Also, the complication rate for anterior/pos-

terior (AP) surgery was not higher compared to posterior only surgery. AP

surgery patients had 182 min longer OR time than posterior only patients,

but no difference in overall EBL (1919 vs. 2006 cc), ICU stay (3.8 vs. 3.7

days), or total hospital stay (13.2 vs. 13.9 days). Coronal curve correction

at final follow up was 61% for the AP patients and 52% for the posterior

only patients (p50.055), but no differences were noted for correction of

pelvic obliquity, kyphosis, instrumentation complications, or caregiver

assessment of utility.

CONCLUSIONS: There does not appear to be a clear advantage of staged

anterior plus posterior surgery compared to same day. When anterior sur-

gery was performed on the same day versus staged, the result was lower

blood loss, operative time and hospital stay without increased complica-

tions. AP surgery as compared with posterior surgery for patients with sco-

liosis due to CP resulted in only modestly better final correction of the

major and minor curves, no difference in pelvic obliquity but required

longer operative time.

FDA DEVICE/DRUG STATUS: This abstract does not discuss or include

any applicable devices or drugs.

doi: 10.1016/j.spinee.2007.07.301

P95. Incidence and Etiology of Transient Nerve Root Injury

with Lumbar Transforaminal Surgery

Walter Eckman, MD1, Michelle McMillen, RN1, Lynda Hester, PT1;1Aurora Spine Center, Tupelo, MS, USA

BACKGROUND CONTEXT: Lumbar transforaminal surgery avoids ab-

dominal anatomy and major vessels allowing access to disk spaces with

minimal displacement of nerve roots. This should theoretically be the saf-

est approach for vertebral interbody device implantation. However, many

surgeons are fearful of transforaminal surgery because of temporary nerve

root injury.

PURPOSE: 1. Determine incidence of nerve root injury with transforami-

nal surgery. 2. Compare rates of injury from diskectomy vs. interbody

fusion. 3. Identify factors which increase nerve root injury in device

implantation procedures.

STUDY DESIGN/SETTING: Prospective study of rates of nerve root in-

jury in patients having transforaminal minimally invasive diskectomy

(TMID) and one or two level minimally invasive transforaminal interbody

fusion (MITLIF).

PATIENT SAMPLE: 110 patients undergoing 111 single level TMID

procedures and 296 patients undergoing 306 single level and 29 two level

MITLIF procedures.

OUTCOME MEASURES: Nerve root injury determined by localized

weakness on motor examination or reports of post-op radicular pain (in

a particular nerve root distribution) not present prior to surgery. Almost

all injuries improve over a few weeks to a few months.

METHODS: A single surgeon performed all procedures with minimally

invasive techniques using 16 to 18mm working channels for TMID and

22 to 28mm working channels for MITLIF. Localization and nerve root ex-

posure were similar but with more foraminal decompression for MITLIF.

51% (57) of TMID procedures included extensive curetting of the disk

space. 49% (54) included only removal of herniated fragments. MITLIF

procedures all included extensive diskectomy, preparation of endplates

with high speed drills or osteotomes, insertion of PEEK or titanium devices

and unilateral pedicle screw fixation.

RESULTS: Risk of Nerve Root Injury: TMID 1.8% (2/111); MITLIF: sin-

gle level 27% (84/306); two level 55% (16/29). Detailed single level MI-

TLIF data: Diabetic: Age: Surgery Level: 34% (10/29) !50 23% (28/121)

L5-S1/L6-S1 19% (18/96) Non-Diabetic: 50–65 26% (28/109) L4-5/L5-6

36% (57/158) 27% (74/277) O65 37% (28/76) L3-4 17% (7/41) L2-3

20% (2/10) L1-2 0% (0/1) Device Height: Device Design: 8,9,10 mm