review article dynamic stabilization for challenging...

Hindawi Publishing CorporationAdvances in OrthopedicsVolume 2013 Article ID 753470 13 pageshttpdxdoiorg1011552013753470

Review ArticleDynamic Stabilization for Challenging Lumbar DegenerativeDiseases of the Spine A Review of the Literature

Tuncay Kaner1 and Ali Fahir Ozer2

1 Department of Neurosurgery School of Medicine Istanbul Medeniyet University 34730 Istanbul Turkey2Department of Neurosurgery School of Medicine Koc University 34365 Istanbul Turkey

Correspondence should be addressed to Ali Fahir Ozer alifahirozergmailcom

Received 30 November 2012 Accepted 7 March 2013

Academic Editor Mehdi Sasani

Copyright copy 2013 T Kaner and A F Ozer This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Fusion and rigid instrumentation have been currently the mainstay for the surgical treatment of degenerative diseases of the spineover the last 4 decades In all over the world the common experience was formed about fusion surgery Satisfactory results oflumbar spinal fusion appeared completely incompatible and unfavorable within years Rigid spinal implants alongwith fusion causeincreased stresses of the adjacent segments and have some important disadvantages such as donor site morbidity including painwound problems infections because of longer operating time pseudarthrosis and fatigue failure of implants Alternative spinalimplants were developed with time on unsatisfactory outcomes of rigid internal fixation along with fusion Motion preservationdevices which include both anterior and posterior dynamic stabilization are designed and used especially in the last two decadesThis paper evaluates the dynamic stabilization of the lumbar spine and talks about chronologically some novel dynamic stabilizationdevices and thier efficacies

1 Introduction

Today low back pain is one of the most important problemin decreasing the quality of life as a result of lumbar discdegeneration [1ndash4] It is thought that the origin of lowback pain results from degenerative intervertebral disc andfacet joints Segmental instability significantly contributedto lower back pain Instability associated with intervertebraldisc degeneration is represented first by Knutsson in 1944[5] Knutsson also described the abnormal flexion-extentionslipping in X-ray along with disc degeneration and toldthat segmental instability should be if sagittal slipping isgreater than 3mm in dynamic X-ray Degeneration processof the lumbar spine and pathology of discogenic pain weredescribed by Kirkaldy-Willis and Farfan in 1982 [2] Theyexplained that degenerative instability of the spine beganprimarily with disc degeneration which contains dehydrationof intervertebral disc along with decrease in tension of theannulus fibrosis It is followed by decrease of disc heightand then this process continues with hypertrophy of thefacet joint and ligamentum flavum At the end spinal stenosis

and degenerative spondylolisthesis which have caused lowback pain occur Besides Frymoyer and Selby revealed theconcept of primary and secondary instabilities and put thedegenerative disc disease degenerative spondylolisthesis anddegenerative scoliotic deformities into the group of primaryinstability [6 7] Panjabi also well defined the term instabilitythat leads to a pain pathological movement deformitiesand neurological inability [8] Afterwards Benzel splittedthe chronic instability to two groups which were glacialinstability and dysfunctional segmental motion [9] Accord-ing to Benzel the commonest sample for glacial instabilityis spondylolisthesis which has been seen as degenerativeisthmic and iatrogenic and for dysfunctional segmentalmotion is degenerative disc disease

Within last century the surgical treatment of disc-relatedpain began with discectomies and decompressions Firstlumbar discectomy surgery has been performed by Mixterand Barr in 1934 [10] However they could not obtain therelief of chronic low back pain after their disc excisionoperation Afterwards radical discectomies and subtotal dis-cectomies have been performed commonly but good clinical

2 Advances in Orthopedics

results have not been obtained and lower back pain andcontinuous sciatica as high as 40 insisted [11ndash14] Insistinglow back pain and sciatica after discectomy procedures havebeen engaged to segmental instability and the concept ofchronic and degenerative instability has been suggested andthen developed within years [2 5ndash9] Some studies showedthat decompression with fusion (posterolateral or inter-body) meaningfully improved patient outcome compared todecompression alone [15ndash18] Fusion was carried out to ceasethe motion for stopping the pain in degenerative disordersof the lumbar spine [19] but every time the achievementcould not been arrived because to fuse the moving spinewas hard [20 21] Later internal fixation systems have beendiscovered by pioneers like Harrington Dick Magerl andRoy Camille and commonly used with fusion [22ndash24] Rigidpedicle screwfixation of spine improves the ratio of successfulfusions according to some biomechanical studies [25]

Rigid internal fixation and fusion have been currentlythe mainstay for surgical treatment of degenerative diseasesof the spine over the last 4 decades In all over the worldthe common experience was formed about fusion surgeryAlthough successful radiological results up to 100 associ-ated with fusion reported this results were not compatiblewith successful clinical outcome regarding pain alleviation[15 26 27] Satisfactory results of lumbar spinal fusion appearcompletely incompatible and ranged from 16 to 95with anaverage of 70 according to a meta-analysis study evaluatedsystematically [28] Rigid spinal implants along with fusionalso cause increased stresses of the adjacent segments andadjacent segment degeneration which is well known isformed [29ndash34] In addition fusion surgery has some impor-tant disadvantages such as donor site morbidity includingpain wound problems infections because of longer operatingtime pseudarthrosis and fatigue failure of implants [35ndash38]

The search for alternative spinal implants was supportedwith time on unsatisfactory outcomes of rigid internalfixation along with fusion The main aim was to avoidthe opposed effects of rigid implants on the stabilized andadjacent segments to prevent the implant failure and toprovide reduced-stress shielding and finally to develop asystem that permits increased load sharing and controlledmotion without cutting off the stability [39] Intervertebraldisc actually has a isotropic architecture like a fluid-filledball but it changes as intervertebral disc is degeneratedIsotropic properties and load transmission of the interverte-bral disc alter depending on disc degeneration [40 41] Theldquostone-in-the-shoerdquo phenomenon explains the postural painpattern in patients suffering from lumbar disc degenerationbecause pattern of loading is related to pain generation inthe degenerated spine which alters one patient to another[41 42] Dynamic stabilization intends to eliminate thepain by delivering the weight with more physiological loadtransmission between anterior and posterior components ofthe spine while attempting to maintain the motion and tocontrol abnormal movement in the spinal segment [42 43](Figure 1) It is supposed that soft or semirigid stabilizationsystems restore normal functions of the spine unit and protectthe adjacent segments [43 44]Dynamic stabilization of spinehas been classified by several authors [4 45 46] Today in

Figure 1 Posterior dynamic stabilization provides more physiolog-ical load transmission between anterior and posterior componentsof the spine

Figure 2 Cosmic posterior dynamic system

market different both anterior and posterior dynamic stabi-lization devices of spine are found Various biomechanicaland clinical studies were done about dynamic stabilizationsystems of spine Recently finite element studies have begunmore and more on these systems Some clinical studiesconcerning dynamic screws and dynamic rods have beenrevealed [37 44 47ndash49] Recently it is thought how we cando the dynamic stabilization systems which is close to morephysiological pattern

2 Indications of DynamicStabilization of Spine

Strempel et al revealed the indications for dynamic stabi-lization with cosmic (semirigid posterior dynamic systemincluding dynamic screw and rigid rod) [50] (Figure 2)These are symptomatic lumbar stenosis chronically recurrent

Advances in Orthopedics 3

lumbago in the case of discogenic pain and facet syndromerecurrent disc herniation in combinationwith a spondylode-sis and extention of an existing spondylodesis in the case of apainful adjacent level degeneration Strempel suggested thatcosmic posterior dynamic stabilization should only be usedfor a maximum of three segments

Khoueir et al revealed the indications for posteriordynamic stabilization in 2007 [45] The indications includedcontrolled motion in the iatrogenically destabilized spineincreased anterior load sharing to augment interbody fusionprotection and restoration of degenerated facet joints andintervertebral discs in combination with anterior motionpreservation for 360 circumferential motion segment recon-struction adaptation of stabilization techniques to the agingspine and the prevention of fusion-related sequelae

Kaner et al described a new classification system aboutdynamic stabilization of spine [4] They reported the indi-cations related to posterior dynamic stabilization systemsThey included degenerative spinal instability (disc degenera-tion facet degeneration and degenerative spondylolisthesis)iatrogenic instability following discectomydecompressivelaminectomy increased anterior load shared to augmentinterbody fusion stabilization of a painful adjacent seg-ment degeneration adjacent to fusion complement TDR toachieve anterior disc replacement and second recurrent of adisc herniation Lomber disc herniations which were gradedIII and IV are based on Carrage Classification system [51]The reherniation rate is quite high in these groups (27) andif surgery is supported with a dynamic system reherniationrate significantly decreases [51 52] They also reported theindications related to interspinous distraction devices whichare central spinal canal stenosis with neurogenic claudicationforaminal stenosis with radicular symptoms and facet jointdisease in one- or two-level stenosis in patients over 50 yearsAs third the indications related to anterior disc prosthesisare patients between 18ndash60 ages (optimally below age 50years) single level or two levels pain due to symptomaticdegenerative disc disease absence of facet joint degenerationchanges existence of intervertebral disc height of at least4mm nonradicular leg pain or back pain postlaminectomysyndrome and patient with positive discogram [4]

3 Anterior Dynamic Stabilization

31 Anterior Disc Prosthesis Lumbar degenerative disc dis-ease is the commonest indication of lumbar disc prosthesisPatients selected for anterior disc prosthesis should be provento have discogenic pain or segmental instability or bothwithout advanced degenerative arthritis However spinalpathology should be demonstrated by routine radiologicalevaluations including upright X-rays magnetic resonanceimaging (MRI) and provocative discography A lumbar discprosthesis may be used to restore discogenic instability andimprove the discogenic pain after discectomy procedure or atplaces of previous discectomy

The history of arthroplasty of spine begins with PaulHarmon from 1959 to 1961 He used vitallium balls throughan anterior approach to stabilize vertebral segments to assist

Figure 3 Charite III artificial lumbar disc prosthesis

Figure 4 ProDisc artificial lumbar disc prosthesis

fusion and realized that some of them could be work wellas stand-alone stabilizers (the first disc arthroplasty) [53]Second specialist who is Ulf Fernstrom from 1962 to 1972used the steel ball arthroplasty of the spine via posteriorlumbar approach [53] The first published article about discarthroplasty belongs to Fernstrom in 1966 [54] Later Reitzand Joubert (1964) [55] and Mc Kenzie (1971) [56] usedsteel ball arthroplasties These specialists imagined and triedearlier disc arthroplasty procedures and motion preservationsurgery In this surgeries ball has an extremely low surfacecontact area on initial implantation which may lead to subsi-dence Pain disc height loss loss of motion and many timesfusionwere seen inmany cases depending on subsidenceTheusage of Fernstrom has been left afterwardsThe first modernprosthesis CHARITE was designed and first implanted byButtner-Janz et al in 1984 [57] First Charite disc prosthesishad a polymer core which is either floating unconstrainedand between two concave end plates Within years ChariteIII (DePuy Spine) was accepted in its final form and certifiedby the FDA in October of 2004 [58] (Figure 3) Today it iswidely used clinically The semiconstrained disc prosthesisdesign ProDisc (Synthes) was implanted first by Rousseauet al in 1990 [59] (Figure 4) CHARITE and ProDisc artificialdisc prostheses have the architecture of hard plateshard coredesignsThere are several artificial disc prosthesis having dif-ferent designThese are hard platessoft core screw-In dowel


Figure 5 Nucleus replacement NuCore and BioDisc


spring and piston and complex mechanicalvertebral bodyreplacement [60] Lumbar disc prosthesis is recommendedL4-L5 and L5-S1 disc levels but especially L4-L5 disc levelis ideal for maintaining the motion This approach is morelogical with regard to the philosophy of motion preservationSatisfactory outcomes are seen after anterior disc prosthesis ifit covers surgical indications Some studies also revealed goodclinical results [61 62]

32 Nucleus Replacement Subcategories of nucleus replace-ment was classified by Buttner-Janz and this classificationhas been made according to following different criteria[63] Group A includes injectable in situ materials anddivided 2 subgroup (1) Uncontained (a) hydrogel adhesiveNuCore and BioDisc (Figures 5 and 6) (b) nonhydrogelnonadhesive Sinux (2) Contained (a) nonhydrogel Dascor(Figure 7) PNR and PDR Group B includes the preformedimplants and divided 2 subgroup (1) Nonarticulating (a)hydrogel PDN-SOLO (Figure 8) Hydraflex Neudisc andAquarella (b) nonhydrogel Newcleus Neodisc and Regain

Figure 7 Nucleus replacement DASCOR

Figure 8 Nucleus replacement PDN SOLO

(2) Articulating (a) same material of components NUBAC(Figure 9) Prosthetic disc nucleus (PDN-Raymedica IncMinneapolis MN) was first implanted in 1996 [64] Thisdevice consists of a polymeric hydrogel pellet surrounded bya high-tenacity polyethylene jacket The aim was cushioningthe intervertebral space for maintaining the function highand flexibility of the normal disc It is transformed fromthe stiff PDN to PDN-SOLO HydraFlex (Raymedica IncMinneapolis MN) is the last form of PDN [64] There aresome clinical studies regarding PDN but the results of studiesare not good [65 66] It is used limitedly today [4]

NuCore is an injectable nucleus which is adhesive andprotein polymer NuCore is injected percutaneously intothe nucleus pulposus as computed tomography guided [63]NuCore is one of the least stiff materials in this group

Kaner et al [4] classified the nucleus replacements intwo fashions (1) nucleus pulposus alternatives that containedthe PDN (PDN-Solo Raymedica LLC) Nubac (InvibioGreenville NC USA) Daskor (Disc dynamics Inc EdenPrairie Minn) and Neudisc (Replication Medical Inc NewBrunswick NJ) and (2) Nucleous Pulposus Supports Biodisc(Cryolife Inc Kennesaw Ga) NuCore IDN (Spine WaveInc Shelton Conn) and Gelifex (Gelifex Inc PhiladelphiaPa)


Figure 9 Nucleus replacement NUBAC

Figure 10 The picture of Henry Graf which used the Graf ligamentsystem

4 Posterior Dynamic Stabilization

Henry Graf used the Graf ligament system (Sem Co Mon-trouce France) which has been called and designed by himas first posterior dynamic stabilization device (Figures 10 and11) Graf ligament was developed by Henry Graf opposite tofusion surgeries This system uses braided polyester bandslooped around the screws instead of rods for providing stabil-itywhile allowingmovementHenryGraf believed that fusionsurgeries had some disadvantages and complications when itwas used in degenerative diseases of the spine and that Grafligament would be enough for conditions of the degenerativeor chronic instability not overt instability He suggested thatsupporting posterior extension band was pretty good inthe treatment of degenerative diseases of the lumbar spineGraf arrived at the achievement with his posterior extentionband named Graf ligament as a novel alternative treatmentopposite to fusion surgery of the lumbar spineThe concept ofGraf rsquos ligament gained popularity primarily in Europe Grafligament as posterior extention band was used in conditionof chronic instability resulted from degenerative diseases ofthe lumbar spine This concept was supported and used [67ndash71] and found inconvenient [72 73] by some surgeons intime Criticism of Graf ligament focused especially on theseconcerns which are ligament loosening foramen narrowingand flat back

Kanayama et al reported 10 year follow-up results ofposterior dynamic stabilization using Graf artificial ligament[71] This report was a retrospective long-term study In thisstudy 56 consecutive patients had artificial Graf ligament but43 patients that suffered from degenerative spondylolisthesis(23 patients) disc herniation with flexion instability (13

Figure 11 Graf ligament system

patients) lumbar spinal stenosis with flexion instability (4patients) and degenerative scoliosis (3 patients) had suffi-cient clinical and radiological followup Patients sufferingfrom degenerative spondylolisthesis and flexion instabilityimproved significantly from symptoms due to low back painand sciatica but patients suffering fromdegenerative scoliosisandor laterolisthesis had poor clinical improvement Theirlong-term results showed that Graf ligamentoplasty was aneffective treatment choice for low-grade spondylolisthesisand flexion instability however it has some limitations tocorrect deformity and is not advocated for the treatment ofdegenerative scoliosis andor laterolisthesis

Choi et al [74] reviewed retrospectively 43 patientstreated with Graf ligamentoplasty for degenerative lum-bar stenosis This study had 8 years follow-up time Theyobserved angular instability translational instability andadjacent segment instability in upper and lower segmentsrespectively 28 7 42 and 30 This study shows thatGraf ligament can be altered by degeneration of the discand facet joints at instrumented segments However theadjacent segment can be affected because of abnormal loadtransmission in Graf ligamentoplasty

Dynesys posterior dynamic stabilization system (ZimmerSpine Inc Warsaw IN) is pedicle screw-based systemfor dynamic stabilization of lumbar spinal segments andwas performed first 1994 [64 75] (Figure 12) Dynesys hascords of polyethylene terephthalate with a tube made frompolycarbonate urethane slid over them and fixed to twoadjacent pedicle screws [4 64] In Dynesys appropriatelength spacer is used to control the degree of distractionand compression on the related segment in contrast to Graftsoft stabilization system Therefore Foramen narrowing andflat back syndrome were avoided by using the spacers inDynesys dynamic system Dynesys approved by FDA in 2004for posterior stabilization system as an adjunct to fusion ofthe lumbar spine [4 46] Dynesys was planned to neutralizeabnormal forces and restored without pain function to thespinal segments while protecting adjacent segments [46 76]Plenty of studies were reported about Dynesys posteriordynamic stabilization system [18 43 76ndash84]


Figure 12 Dynesys posterior dynamic stabilization system

Stoll et al [78] reported 83 consecutive patients whooperated because of lumbar spinal stenosis degenerative discdisease disc herniation and revision surgery The meanfollow-up time was 381 months Their implant-related com-plications were two screw displacement and screw looseningon radiograph The one patient of screw displacement wasreoperated because of root compression and improved Justone patient was reoperated because of the loosening of twobilateral screws and screws were removed and have not beenput again Besides there were 9 complications unrelated to theimplant Seven patients had adjacent segment degenerationand have been reoperated Mean Oswestry score was 554preoperatively and went down to 229 postoperatively Thisimprovement was found statistically meaningful (119875 lt 001)Authors suggested in this study thatDynesys was less invasiveand theoretically produced less degeneration of adjacentsegments

Putzier et al [77] reported the compared nucleotomyprocedure for the surgical treatment of the lumbar discprolapse without or with posterior dynamic stabilizationwithDynesys 84 patients underwent nucleotomy procedure andDynesys was carried out to 35 of them There were MODIC1 disc degeneration signs in all patients The mean follow-up duration was 34 months This study showed that thepatients with additional stabilization with Dynesys revealedmeaningful less signs of progressive degeneration

Schaeren et al reported 26 consecutive patients sufferingfrom lumbar spinal stenosis and degenerative spondylolis-thesis [85] They performed decompression and posteriordynamic stabilization with Dynesys Their mean follow-upduration was 52 months Patients were evaluated clinicallyand radiographically during followup Patients satisfactionwas obtained high as 95 Implant failure screw looseningwas observed in 3 patients in 2 years after operation howevernobody was reoperated related for that 2 of these patientswere asymptomatic and other had low back pain Theyobserved one instability related to a screw breakage in apatient and adjacent segment degeneration in 9 patients(47) after four years

Schnake et al [18] reported in their prospective clinicalstudy a total of 26 patients with lumbar spinal stenosis withdegenerative spondylolisthesis who underwent interlaminardecompression and dynamic stabilization with the Dynesysposterior dynamic system They concluded that Dynesysmaintains enough stability to prevent further progression ofinstability Otherwise they mentioned that Dynesys stabiliza-tion system does not need using bone Grafting

Some studies were done regarding the effects of Dynesyson adjacent segments Schmoelz et al [86] reported in anin vitro study that Dynesys provided substantial stabilitywhile allowing more movement in the stabilized segment indegenerative spinal disorders and therefore it is considered asan alternative method to fusion surgery On the other handadjacent segments appear to be not influenced by the stiffnessof the fixation procedure Cakir et al researched adjacentsegment mobility after rigid and semirigid instrumentationsof the lumbar spine [81] They study included 26 patientswith low back pain and neurogenic claudication due toL4-L5 degenerative instability and spinal stenosis Patientsoperated either with decompression and Dynesys posteriorstabilization (119899 = 11) or with decompression and fusion(119899 = 15) Range of motion was evaluated at L4-L5 which isindex level and adjacent segments which are L3-L4 and L5-S1 They obtained that monosegmental dynamic stabilizationalong with Dynesys has no beneficial effect on adjacentsegment mobility compared with monosegmental fusionand instrumentation Kumar et al [80] reported in theirprospective case series including 32 patients who underwentjust posterior dynamic stabilization with Dynesys (119899 =20) and additional fusion at one or more levels that discdegeneration at the bridged and adjacent segment seems tocontinue despite Dynesys dynamic stabilization

Grob et al [79] revealed the clinical experience withDynesys stabilization system This study was composed ofretrospective 50 consecutive case series All of them instru-mented with Dynesys 31 patients were followed-up withquestionnaire at least 2 yearsTheir result showed that qualityof life and improvements in functional capacity were justmoderate Around 50 patients stated that the operationhelped or helped a lot There was no superiority of Dynesyssystem compared with fusion surgery

Cosmic semirigid posterior dynamic system is composedof dynamic screw and rigid rod Dynamic screw was firstused and accepted as a new concept by Strempel in 1999[47] Strempel built a dynamic screw with a hinge placedbetween the head and body of the screw (Cosmic UlrichAG Germany) [47 50 87] Posterior dynamic transpedicularhinged-screw along with rigid rod system enables potentialsagittal movement between the screw head and the screwbody This system allows limited motion which occursbetween hinged screw head and the longitudinally placedrod during flexion-extention behavior of the spine Cosmictranspedicular dynamic system provides the load sharingon bridged segment and part of the load placed on thespine is transferred by the system hereby the effect of thestress shielding on the bones reduced [50 86 87] Bozkuset al showed that dynamic stabilization provides a stabilitythat is similar to that provided by rigid systems and that


Figure 13 Saphinas dynamic screw

Figure 14 The Isobar TLL dynamic rod

the hinged-dynamic screws allow less stress shielding thanstandard rigid screws in their in vitro biomechanical studywhich had used the dynamichinged pedicular screw-rodsystem [88] Another hinged transpedicular screw-rigid rodsystem is fromTurkey and its name is Safinas Dynamic Screw(Medikon Turkey) (Figure 13) Safinas hinged screw workssimilarly to cosmic screw and allows the limited motion inflexion and extention behavior of the spine but it controlsdisplacement rotation and translation There are some bothclinical [37 44 47ndash50 52 66 89] and biomechanical [25 3986 88] studies about dynamic screw-rod stabilization system

Kaner et al [37] reported the compared study of dynamicstabilization with cosmic dynamic screw-rod and posteriorrigid transpedicular stabilizationwith fusion to treat degener-ative spondylolisthesis This clinical and radiological studieswere conducted between 2004 and 2007 and containedtotally 46 patients Twenty-six patients operated via cosmicposterior dynamic stabilization were followed-up at averageof 38 months and fusion group with rigid stabilization thatincluded twenty patients was followed-up at average of 44months There were similar results in both groups as a resultof VAS Oswestry the measurements of lumbar lordosis andsegmental lordosis angle after two years of followup Onthe other hand intervertebral space ratios in the cosmic

Figure 15 The rod of the CD Horizon Agile

posterior dynamic stabilization group were obtained to bestatisticallymeaningful higher than those in the fusion groupIn conclusion of this study it was thought that the discdistance is maintained and disc degeneration is slowed downafter using posterior dynamic transpedicular stabilization

Another compared study of safinas lumbar pediculardynamic screw-rod and fusion was done by Ozer et al [48]Equivalent relief of pain and maintenance of sagittal balancewere seen compared with safinas lumbar pedicular dynamicscrew-rod and standard rigid screw-rod fixation

The Isobar TLL Dynamic Rod (Scientrsquox Maitland FL) iscomposed of TiAIV alloy and attached between rigid screws(monoaxial or polyaxial) [64] (Figure 14) The Isobar semi-rigid spinal system (ScientrsquoXrsquos Isobar) received FDA clearancefor using as an adjunct to lumbar fusions in November 1999Isobar TLL semirigid rod allows some limited movement infusion place It is aimed by manufacturer that it can promotefusion ratio on the instrumented segment and decreaseadjacent segment degeneration via protecting the adjacentdisc from excessive stress [90] Zhang et al studied theeffectiveness of ISOBARTTL semirigid dynamic stabilizationsystem in treatment of lumbar degenerative disease [91]Thisstudy was done between 2007 and 2011 on 38 patients whichare treated because of lumbar degenerative diseaseThemeanfollow-up duration in this study was 278 months The resultsof this study showed that Isobar TLL had reliable fixation andno loosening breakage and adjacent segment degenerationAuthors suggested that Isobar TLL had good short-termeffectiveness in treatments of lumbar degenerative diseaseAnother biomechanical study using cadaveric human lumbarspine reported that Isobar TLL device may stabilize only theanterior colon [92]

The rod of the CD Horizon Agile (Medtronic SofamorDanek Memphis TN) is dynamic stabilization device [4 64]andwas used as single level and adjacent to fusion (Hybrid) intwo forms (Figure 15) It was developed for using along withrigid rods in 2007 [44] Dynamic Agile rod was deformeddue to overloading and stress in clinical usage in time As aresult it has been removed from the market and terminatedof its production [44] It is the first study that has been doneutilizing dynamic rods with dynamic screws in treatmentof chronic instability [44] CD Horizon Agile used Safinasdynamic screws and good clinical results were observed inthis clinical study [44]

NFlex (N spine Inc San Diego CA) is a dynamicstabilization system [64] (Figure 16) It is composed of twoparts polyaxial rigid screw and titanium and polycarbonate


Figure 16 NFlex dynamic stabilization system

urethane rod NFlex is first implanted in 2006 A mul-ticenter study was performed related to NFlex dynamicstabilization system [93] In this retrospective study 72consecutive patients who have degenerative diseases of thespine underwent surgery with NFlex dynamic system Meanfollowupwas 256months VAS andOswestry disability indexof the patients were improved obviously after operationsJust three implant-related complications were observed Thisstudy showed that NFlex dynamic system seems to improvepain and functional scores and may be considered a goodalternative to rigid fusion [93]

AXIENT dynamic stabilization system (Innovative SpinalTechnologies Mansfield MA) is composed of rigid pediclescrews and articulates CoCr sliding rods with a part fordepressing during extention which is made of carbonate ure-thane [64] This system permits segmental motion providedto avoid excessive motion in flexion extention and axialrotation

Accuflex rod system (Globus Medical Inc) is a semirigidrod which has been situated between rigid rods Accuflexsystem obtained FDA clearance in 2005 as a single-leveltool to stabilize lumbar interbody fusion [46] A clinicalstudy was done related to Accuflex rod system This studyreported that Accuflex semirigid system showed clinicalbenefits and ceased the degenerative process in 83 of thepatients although high incidence of implant failure (2222)was observed [94]

CDHorizon legacy peek rod (Medtronic SafamorDanekMemphis TN) has been introduced to the market as a semi-rigid alternative to titanium rods (Figure 17) FDA clearancehas been got in June 2005 In a biomechanical study Gornetet al reported that peek rod system provided intervertebralstability comparable to currently marketed titanium lumbarfusion constructs [95] Ormond et al studied retrospective42 case series from 2007 to 2009 for degenerative lumbardisease and performed them posterior lumbar fusion usingPEEK rods [96] They observed that 8 of 42 patients withPEEK rods underwent reoperation Reoperations included

Figure 17 CD horizon legacy peek rod

Figure 18 The Stabilimax NZ which is a pedicle-based posteriordynamic system

adjacent segment degeneration (58) and nonunionwith cagemigration (35) In conclusion authors reported that PEEKrods demonstrated similar fusion and reoperation rate incomparison with other instrumentation modalities

The Stabilimax NZ (Applied Spine Technologies NewHaven CT) is a pedicle-based posterior dynamic systemwhich was developed and designed to specifically addresspathological alterations in the neutral zone by Panjabi [9798] (Figure 18) Its indications include moderate to severedegenerative lumbar spinal stenosis and discogenic low backpain The Stabilimax NZ is composed of a system of ball andsocket joints to decrease the load on the pedicle screw anddouble connecting springs [46 97 98]

5 Total Facet Replacement Systems

Total facet replacement systems are designed to totallyrestore facet joints functionally The degeneration of facetjoints generally results from intervertebral disc degenerationbecause of this reason facetogenic pain can occur along withsevere disc degeneration and it may be used in significantfacet and intervertebral disc degeneration either alone orwith total disc arthroplasty [45] Total facet replacementsystems can be used at the situation of reconstruction ofthe spine due to iatrogenic facetectomy [45 64] There are


Figure 19 The total posterior arthroplasty system (TOPS)

Figure 20 The total facet arthroplasty system (TFAS)

some total facet replacement systems such as the total facetarthroplasty system (TFAS) the total posterior arthroplastysystem (TOPS) (Figure 19) and anatomic facet replacementsystem (AFRS) [4 45 46 64] TFAS (Archus OrthopedicsInc Redmond WA) completely restores the total joints andis totally made of metal [64] (Figure 20) It is nonfusionspinal implant and is developed for severe facet degenerationwith lumbar spinal stenosis It needs total laminectomy andfacet resection for the implantation of TFAS TOPS (ImpliantSpine Princeton NJ) is composed of metal and plasticmaterial and a pedicle screw-based systems [45 46 64] Pos-terior facets and lamina are resected totally and nonfusionTOPS device which enables physiologic range of motionis implanted It is thought that TOPS preserves motionprevents abnormal load sharing at both adjacent and treatedsegments and restores the neutral zone [99] Nowadays thereare several clinical and biomechanical studies on total facetreplacement systems and similar facet replacement systemshaving the same properties have been developed for clinicalusage [45]

6 Posterior Interspinous Spacer Devices

Lumbar interspinous spacer devices have recently been popu-lar for alternative treatment of lumbar degenerative diseasesInterspinous spacer devices are used in lumbar spine from L1

Figure 21 Wallis posterior interspinous spacer device

to L5 for treatment of central spinal canal stenosis with neu-rogenic claudication foraminal stenosis facet joint diseaseand the dorsal disc anloading in extention [4 64] One ofthe first interspinous spacer devices has been developed forlumbar stabilization in 1986 and was called as wallis system[100] Wallis system (Abbott Spine Inc Austin TX) consistsof two parts these are PEEK and two woven polyester bands(Figure 21) The first implant was developed and in 2002 asecond generation of the wallis implant has been produced[64 101] Senegas et al who developed the wallis devicereported the clinical evaluation of the wallis interspinousspacer device with a 13-year mean followup They reported107 patients who filled out the health questionnaires Allpatients had schedule for fusion surgery because of lumbarcanal stenosis and lumbar disc herniation or both While 87patients have still interspinous spacer today other 20 patientsexperienced implant removing and had reoperation as fusionThey concluded that wallis provided good clinical results atlast 13 years and 80 of patients were protected from fusionsurgery and living now with posterior dynamic stabilizationSome similar systems have been produced and offered to themarket Some of them are Coflex (Paradigm Spine LLC NewYork NY) (Figure 22) the device for intervertebral assistedmotion (DIAM) (Medtronic Sofamor Danec Memphis TN)(Figure 23) the Fulcrum-assisted soft stabilization (FASS)The superion spacer (VertiFlex Inc San Clemente CA)and X-STOP (Kyphon Inc Sunnyvale CA) (Figure 24)[4 64 101] Kabir et al [102] studied on a systematicreview of clinical and biomechanical evidence about lumbarinterspinous spacers They reported that the biomechani-cal studies with all the devices showed that interspinousspacer devices have a beneficial effect on the kinematics ofthe degenerative spine They also mentioned that Lumbarinterspinous spacer devices may have a potential beneficialeffect in selected group of patients with degenerative diseaseof the lumbar spine A new biomechanical study about X-STOP showed that implantation of the X-Stop devices caneffectively distract the interspinous process space at thediseased level without causing apparent kinematic changesat the adjacent segments during the studied postures [103]In other study being randomized controlled prospectivemulticenter trial Zucherman et al suggested that the X-STOPprovides a conservative yet effective treatment for patientssuffering from lumbar spinal stenosis and the X-STOP may


Figure 22 Coflex posterior interspinous spacer device

Figure 23 The device for intervertebral assisted motion (DIAM)

be alternative treatment to both decompressive spine surgeryand conservative treatment [104]

7 Conclusion

Nowadays in market different both anterior and posteriordynamic stabilization devices of the lumbar spine are foundVarious both biomechanical and clinical studies have beenmade about dynamic stabilization systems of the lumbarspine Recently finite element studies also have been begunmore and more on these systems Dynamic stabilizationsystems of lumbar spine on rigid stabilization have someadvantages such as increased load sharing and controlledmotion without cutting off the stability which could be animportant factor in decreasing adjacent segment degener-ation but this matter has not been yet proved clearly Inthe future it needs prospective compared clinical studies forproviding the benefit of dynamic stabilization systems

Figure 24 X-STOP posterior interspinous spacer device

Conflict of Interests

None of the authors has a secondary interest such as financialgain and a conflict of interest with thementioned commercialidentities in this manuscript

References

[1] A C Schwarzer C N Aprill R Derby J Fortin G Kineand N Bogduk ldquoThe relative contributions of the disc andzygapophyseal joint in chronic low back painrdquo Spine vol 19 no7 pp 801ndash806 1994

[2] WHKirkaldy-Willis andH F Farfan ldquoInstability of the lumbarspinerdquo Clinical Orthopaedics and Related Research vol 165 pp110ndash123 1982

[3] S D Kuslich C L Ulstrom andC JMichael ldquoThe tissue originof low back pain and sciatica a report of pain response to tissuestimulation during operations on the lumbar spine using localanesthesiardquo Orthopedic Clinics of North America vol 22 no 2pp 181ndash187 1991

[4] T Kaner M Sasani T Oktenoglu and A F Ozer ldquoDynamicstabilization of the spine a new classification systemrdquo TurkishNeurosurgery vol 20 no 2 pp 205ndash215 2010

[5] F Knutsson ldquoThe instability associated with disc degenerationin the lumbar spinerdquo Acta Radiologica vol 25 pp 593ndash6091944

[6] J W Frymoyer ldquoSegmental instabilityrdquo inThe Adult Spine J WFrymoyer Ed pp 1873ndash1891 Raven Press New York NY USA1991

[7] JW Frymoyer andD K Selby ldquoSegmental instability rationalefor treatmentrdquo Spine vol 10 no 3 pp 280ndash286 1985

[8] M M Panjabi ldquoClinical spinal instability and low back painrdquoJournal of Electromyography and Kinesiology vol 13 no 4 pp371ndash379 2003

[9] E C Benzel ldquoStability and instability of the spinerdquo in Biome-chanics of Spine Stabilization pp 29ndash43 AANS New York NYUSA 2001

[10] W J Mixter and J S Barr ldquoRupture of the intervertebral discwith involvement of the spinal canalrdquoThe New England Journalof Medicine vol 211 pp 210ndash215 1934

[11] H Striffeler U Groger and H J Reulen ldquo10158401015840Standard10158401015840 micro-surgical lumbar discectomy vs 10158401015840Conservative10158401015840 microsurgical


discectomy a preliminary studyrdquoActa Neurochirurgica vol 112no 1-2 pp 62ndash64 1991

[12] W Caspar B Campbell D D Barbier R Kretschmmer andY Gotfried ldquoThe Caspar microsurgical discectomy and com-parison with a conventional standard lumbar disc procedurerdquoNeurosurgery vol 28 no 1 pp 78ndash87 1991

[13] P A Vaughan B W Malcolm and G L Maistrelli ldquoResults ofL4-L5 disc excision alone versus disc excision and fusionrdquo Spinevol 13 no 6 pp 690ndash695 1988

[14] R W Hu S Jaglal T Axcell and G Anderson ldquoA population-based study of reoperations after back surgeryrdquo Spine vol 22no 19 pp 2265ndash2271 1997

[15] K H Bridwell T A Sedgewick M F OrsquoBrien L G Lenkeand C Baldus ldquoThe role of fusion and instrumentation inthe treatment of degenerative spondylolisthesis with spinalstenosisrdquo Journal of Spinal Disorders vol 6 no 6 pp 461ndash4721993

[16] R J Nasca ldquoRationale for spinal fusion in lumbar spinalstenosisrdquo Spine vol 14 no 4 pp 451ndash454 1989

[17] H L Feffer S W Wiesel J M Cuckler and R H RothmanldquoDegenerative spondylolisthesis to fuse or not to fuserdquo Spinevol 10 no 3 pp 287ndash289 1985

[18] K J Schnake S Schaeren and B Jeanneret ldquoDynamic stabi-lization in addition to decompression for lumbar spinal stenosiswith degenerative spondylolisthesisrdquo Spine vol 31 no 4 pp442ndash449 2006

[19] R B Cloward ldquoThe treatment of ruptured lumbar interver-tebral discs by vertebral body fusion I Indications operativetechnique after carerdquo Journal of Neurosurgery vol 10 no 2 pp154ndash168 1953

[20] T Andersen F B Christensen E S Hansen and C BungerldquoPain 5 years after instrumented and non-instrumented pos-terolateral lumbar spinal fusionrdquo European Spine Journal vol12 no 4 pp 393ndash399 2003

[21] A F DePalma and R H Rothman ldquoThe nature of pseudarthro-sisrdquo Clinical Orthopaedics and Related Research vol 59 pp 113ndash118 1968

[22] P R Harrington ldquoThe history and development of Harringtoninstrumentationrdquo Clinical Orthopaedics vol 93 pp 110ndash1121973

[23] R Roy-Camille M Roy-Camille and C DemeulenaereldquoOsteosynthesis of dorsal lumbar and lumbosacral spine withmetallic plates screwed into vertebral pedicles and articularapophysesrdquo La Presse Medicale vol 78 no 32 pp 1447ndash14481970

[24] W Dick P Kluger F Magerl O Woersdorfer and G Zach ldquoAnew device for internal fixation of thoracolumbar and lumbarspine fractures the rsquofixateur internersquordquo Paraplegia vol 23 no 4pp 225ndash232 1985

[25] J L Scifert K Sairyo V K Goel et al ldquoStability analysisof an enhanced load sharing posterior fixation device and itsequivalent conventional device in a calf spinemodelrdquo Spine vol24 no 21 pp 2206ndash2213 1999

[26] N Boos and J K Webb ldquoPedicle screw fixation in spinaldisorders a European viewrdquo European Spine Journal vol 6 no1 pp 2ndash18 1997

[27] K C Booth KH Bridwell B A Eisenberg C R Baldus and LG Lenke ldquoMinimum5-year results of degenerative spondylolis-thesis treated with decompression and instrumented posteriorfusionrdquo Spine vol 24 no 16 pp 1721ndash1727 1999

[28] J A Turner M Ersek L Herron and R Deyo ldquoSurgeryfor lumbar spinal stenosis attempted meta-analysis of theliteraturerdquo Spine vol 17 no 1 pp 1ndash8 1992

[29] P V Mummaneni R W Haid and G E Rodts ldquoLumbarinterbody fusion state-of-the-art technical advancesrdquo Journalof Neurosurgery vol 101 no 1 pp 24ndash30 2004

[30] J GlaserM Stanley H Sayre JWoody E Found andK SprattldquoA 10-year follow-up evaluation of lumbar spine fusion withpedicle screw fixationrdquo Spine vol 28 no 13 pp 1390ndash13952003

[31] P Fritzell O Hagg D Jonsson and A Nordwall ldquoSwedishLumbar Spine Study Group Cost effectiveness of lumbarfusion and nonsurgical treatment for chronic low back painin the Swedish lumbar spine study a multicenter randomizedcontrolled trial from the Swedish lumbar spine study grouprdquoSpine vol 29 no 4 pp 421ndash434 2004

[32] P C McAfee I D Farey C E Sutterlin K R Gurr K EWarden and B W Cunningham ldquoThe effect of spinal implantrigidity on vertebral bone density a canine modelrdquo Spine vol16 no 6 pp S190ndashS197 1991

[33] T R Lehmann K F Spratt J E Tozzi et al ldquoLong-term follow-up of lower lumbar fusion patientsrdquo Spine vol 12 no 2 pp 97ndash104 1987

[34] M D Rahm and B B Hall ldquoAdjacent-segment degenerationafter lumbar fusionwith instrumentation a retrospective studyrdquoJournal of Spinal Disorders vol 9 no 5 pp 392ndash400 1996

[35] E M Younger and M W Chapman ldquoMorbidity at bone graftdonor sitesrdquo Journal of Orthopaedic Trauma vol 3 no 3 pp192ndash195 1989

[36] J C Banwart M A Asher and R S Hassanein ldquoIliac crestbone graft harvest donor sitemorbidity a statistical evaluationrdquoSpine vol 20 no 9 pp 1055ndash1060 1995

[37] T Kaner S Dalbayrak T Oktenoglu M Sasani A L AydinandFOOzer ldquoComparison of posterior dynamic andposteriorrigid transpedicular stabilization with fusion to treat degenera-tive spondylolisthesisrdquo Orthopedics vol 33 no 5 2010

[38] J L West J W Ogilvie and D S Bradford ldquoComplications ofthe variable screw plate pedicle screw fixationrdquo Spine vol 16 no5 pp 576ndash579 1991

[39] H Z Xu X YWang Y L Chi et al ldquoBiomechanical evaluationof a dynamic pedicle screw fixation devicerdquoClinical Biomechan-ics vol 21 no 4 pp 330ndash336 2006

[40] D S McNally and M A Adams ldquoInternal intervertebral discmechanics as revealed by stress profilometryrdquo Spine vol 17 no1 pp 66ndash73 1992

[41] R P Nockels ldquoDynamic stabilization in the surgical manage-ment of painful lumbar spinal disordersrdquo Spine vol 30 no 16pp S68ndashS72 2005

[42] D K Sengupta ldquoDynamic stabilization devices in the treatmentof low back painrdquo Neurology India vol 53 no 4 pp 466ndash4742005

[43] M Bothmann E Kast G J Boldt and J Oberle ldquoDynesysfixation for lumbar spine degenerationrdquo Neurosurgical Reviewvol 31 no 2 pp 189ndash196 2008

[44] T Kaner M Sasani T Oktenoglu M Cosar and A F OzerldquoUtilizing dynamic rods with dynamic screws in the surgicaltreatment of chronic instability a prospective clinical studyrdquoTurkish Neurosurgery vol 19 no 4 pp 319ndash326 2009

[45] P Khoueir K A Kim and M Y Wang ldquoClassification ofposterior dynamic stabilization devicesrdquo Neurosurgical Focusvol 22 no 1 article E3 2007


[46] C M Bono M Kadaba and A R Vaccaro ldquoPosterior pediclefixation-based dynamic stabilization devices for the treatmentof degenerative diseases of the lumbar spinerdquo Journal of SpinalDisorders and Techniques vol 22 no 5 pp 376ndash383 2009

[47] T Oktenoglu A F Ozer M Sasani et al ldquoPosterior dynamicstabilization in the treatment of lumbar degenerative discdisease 2-year follow-uprdquoMinimally InvasiveNeurosurgery vol53 no 3 pp 112ndash116 2010

[48] A F Ozer N R Crawford M Sasani et al ldquoDynamic lumbarpedicle screw-rod stabilization two-year follow-up and com-parison with fusionrdquoThe Open Orthopaedics Journal vol 4 pp137ndash141 2010

[49] T Kaner M Sasani T Oktenoglu et al ldquoMinimum two-year follow-up of cases with recurrent disc herniation treatedwith microdiscectomy and posterior dynamic transpedicularstabilisationrdquo The Open Orthopaedics Journal vol 4 pp 120ndash125 2010

[50] A V Strempel D Moosmann C Stoss and A MartinldquoStabilisation of the degenerated lumbar spine in the nonfusiontechnique with cosmic posterior synamic systemrdquo The WallStreet Journal vol 1 no 1 pp 40ndash47 2006

[51] E J Carragee M Y Han P W Suen and D Kim ldquoClinicaloutcomes after lumbar discectomy for sciatica the effects offragment type and anular competencerdquo Journal of Bone andJoint Surgery A vol 85 no 1 pp 102ndash108 2003

[52] T Kaner M Sasani T Oktenoglu M Cosar and A F OzerldquoClinical outcomes after posterior dynamic transpedicular sta-bilization with limited lumbar discectomy carragee classifica-tion system for lumbar disc herniationsrdquo SAS Journal vol 4 no3 pp 92ndash97 2010

[53] A H McKenzie ldquoThe basis for motion preservation surgerylessons learned from the pastrdquo in Motion Preservation Surgeryof the Spine J J Yu R Bertagnoli P C McAfee and H S AnEds pp 3ndash10 Saunders Elsevier Press Philadelphia Pa USA2008

[54] U Fernstrom ldquoArthroplasty with intercorporal endoprothesisin herniated disc and in painful discrdquo Acta Chirurgica Scandi-navica Supplement vol 357 pp 154ndash159 1966

[55] H Reitz and M J Joubert ldquoReplacement of cervical interverte-bral discwith ametal prosthesisrdquo SouthAfricanMedical Journalvol 38 pp 881ndash884 1964

[56] A H Mc Kenzie ldquoSteel ball arthroplasty of lumbar discsrdquoJournal of Bone and Joint Surgery vol 54 article 266 1972

[57] K Buttner-Janz K Schellnack and H Zippel ldquoBiomechanicsof the SB Charite lumbar intervertebral disc endoprosthesisrdquoInternational Orthopaedics vol 13 no 3 pp 173ndash176 1989

[58] R D Guyer P CMcAfee S H Hochschuler et al ldquoProspectiverandomized study of the Charite artificial disc data from twoinvestigational centersrdquo Spine Journal vol 4 no 6 pp 252ndash2592004

[59] M A Rousseau D S Bradford R Bertagnoli S S Hu andJ C Lotz ldquoDisc arthroplasty design influences intervertebralkinematics and facet forcesrdquo Spine Journal vol 6 no 3 pp 258ndash266 2006

[60] R K Sethi L N Metz and D S Bradford ldquoHistory andevolution of motion preservationrdquo in Motion PreservationSurgery of the Spine J J Yu R Bertagnoli P C McAfee andH S An Eds pp 11ndash20 Saunders Elsevier Press PhiladelphiaPa USA 2008

[61] M Sasani T Oktenoglu K Tuncay N Canbulat S Carilli andF A Ozer ldquoTotal disc replacement in the treatment of lumbar

discogenic pain with disc herniation a prospective clinicalstudyrdquo Turkish Neurosurgery vol 19 no 2 pp 127ndash134 2009

[62] J C Le Huec H Mathews Y Basso et al ldquoClinical results ofMaverick lumbar total disc replacement two-year prospectivefollow-uprdquo Orthopedic Clinics of North America vol 36 no 3pp 315ndash322 2005

[63] K Buttner-Janz ldquoPercutaneous application of nucleus replace-mentsrdquo inProceedings of the 2nd International Congress Biotech-nologies for Spinal Surgery (BIOSPINE rsquo07) Leipzig GermanySeptember 2007

[64] K Buttner-Janz ldquoClassification of spine arthroplasty devicesrdquo inMotion Preservation Surgery of the Spine J J Yu R BertagnoliP C McAfee and H S An Eds pp 21ndash35 Saunders ElsevierPress Philadelphia Pa USA 2008

[65] L Pimenta PDN at 5 Years Follow-Up Spine ArthroplastySociety Montreal Canada 2006

[66] M Sasani A L Aydin T Oktenoglu et al ldquoThe combined useof a posterior dynamic transpedicular stabilization system anda prosthetic disc nucleus device in treating lumbar degenerativedisc disease with disc herniationsrdquo SAS Journal vol 2 no 3 pp130ndash136 2008

[67] A Gardner and K C Pande ldquoGraf ligamentoplasty a 7-yearfollow-uprdquo European Spine Journal vol 11 no 2 pp S157ndashS1632002

[68] M Kanayama T Hashimoto and K Shigenobu ldquoRationalebiomechanics and surgical indications for graf ligamento-plastyrdquo Orthopedic Clinics of North America vol 36 no 3 pp373ndash377 2005

[69] M Kanayama T Hashimoto K Shigenobu et al ldquoAdjacent-segment morbidity after Graf ligamentoplasty compared withposterolateral lumbar fusionrdquo Journal of Neurosurgery vol 95no 1 pp 5ndash10 2001

[70] A Onda K Otani S Konno and S Kikuchi ldquoMid-termand long-term follow-up data after placement of the Grafstabilization system for lumbar degenerative disordersrdquo Journalof Neurosurgery Spine vol 5 no 1 pp 26ndash32 2006

[71] M Kanayama T Hashimoto K Shigenobu D Togawa andF Oha ldquoA minimum 10-year follow-up of posterior dynamicstabilization using graf artificial ligamentrdquo Spine vol 32 no 18pp 1992ndash1996 2007

[72] M Rigby G Selmon M Foy and A Fogg ldquoGraf ligamentstabilisation mid- to long-term follow-uprdquo European SpineJournal vol 10 no 3 pp 234ndash236 2001

[73] Z Askar DWardlaw TMuthukumar F Smith D Kader and SGibson ldquoCorrelation between inter-vertebral disc morphologyand the results in patients undergoing Graf ligament stabilisa-tionrdquo European Spine Journal vol 13 no 8 pp 714ndash718 2004

[74] Y Choi K Kim and K So ldquoAdjacent segment instability aftertreatment with a graf ligament at minimum 8 yearsrsquo followuprdquoClinical Orthopaedics and Related Research vol 467 no 7 pp1740ndash1746 2009

[75] G Dubois B de Germay N S Schaerer and P FennemaldquoDynamic neutralization a new concept for restabilization ofthe spinerdquo in Lumbal Segmental Instability M Szpalski RGunzburg and M H Pope Eds pp 233ndash240 LippincottWilliams and Wilkins Philadelphia Pa USA 1999

[76] O Schwarzenbach U Berlemann T M Stoll and G DuboisldquoPosterior dynamic stabilization systems DYNESYSrdquo Orthope-dic Clinics of North America vol 36 no 3 pp 363ndash372 2005

[77] M Putzier S V Schneider J F Funk S W Tohtz and CPerka ldquoThe surgical treatment of the lumbar disc prolapse


nucleotomy with additional transpedicular dynamic stabiliza-tion versus nucleotomy alonerdquo Spine vol 30 no 5 pp E109ndashE114 2005

[78] T M Stoll G Dubois and O Schwarzenbach ldquoThe dynamicneutralization system for the spine a multi-center study of anovel non-fusion systemrdquo European Spine Journal vol 11 no2 pp S170ndashS178 2002

[79] D Grob A Benini A Junge and A F Mannion ldquoClinicalexperience with the dynesys semirigid fixation system for thelumbar spine surgical and patient-oriented outcome in 50 casesafter an average of 2 yearsrdquo Spine vol 30 no 3 pp 324ndash3312005

[80] A Kumar J Beastall J Hughes et al ldquoDisc changes in thebridged and adjacent segments afterDynesys dynamic stabiliza-tion system after two yearsrdquo Spine vol 33 no 26 pp 2909ndash29142008

[81] B Cakir C Carazzo R Schmidt T Mattes H Reichel andW Kafer ldquoAdjacent segment mobility after rigid and semirigidinstrumentation of the lumbar spinerdquo Spine vol 34 no 12 pp1287ndash1291 2009

[82] S Vaga M Brayda-Bruno F Perona et al ldquoMolecular MRimaging for the evaluation of the effect of dynamic stabilizationon lumbar intervertebral discsrdquo European Spine Journal vol 18no 1 pp S40ndashS48 2009

[83] B Cakir M Richter K Huch W Puhl and R SchmidtldquoDynamic stabilization of the lumbar spinerdquo Orthopedics vol29 no 8 pp 716ndash722 2006

[84] O Ricart and J M Serwier ldquoDynamic stabilisation and com-pression without fusion using Dynesys for the treatment ofdegenerative lumbar spondylolisthesis a prospective series of25 casesrdquo Revue de Chirurgie Orthopedique et Reparatrice delrsquoAppareil Moteur vol 94 no 7 pp 619ndash627 2008

[85] S Schaeren I Broger and B Jeanneret ldquoMinimum four-yearfollow-up of spinal stenosis with degenerative spondylolisthesistreated with decompression and dynamic stabilizationrdquo Spinevol 33 no 18 pp E636ndashE642 2008

[86] W Schmoelz U Onder A Martin and A von Strempel ldquoNon-fusion instrumentation of the lumbar spine with a hingedpedicle screw rod system an in vitro experimentrdquo EuropeanSpine Journal vol 18 no 10 pp 1478ndash1485 2009

[87] A Strempel A Neekritz P Muelenaere et al ldquoDynamic versusrigid spinal implantsrdquo in Lumbar Spinal Stenosis R Gunzburgand M Szpalski Eds pp 275ndash285 Lippincott-Williams andWilkins Philadelphia Pa USA 2000

[88] H Bozkus M Senoglu S Baek et al ldquoDynamic lumbar pediclescrew-rod stabilization in vitro biomechanical comparisonwith standard rigid pedicle screw-rod stabilizationmdashlaboratoryinvestigationrdquo Journal of Neurosurgery Spine vol 12 no 2 pp183ndash189 2010

[89] T Kaner M Sasani T Oktenoglu A L Aydin and A FOzer ldquoClinical outcomes of degenerative lumbar spinal stenosistreated with lumbar decompression and the Cosmic rdquosemi-rigidrdquo posterior systemrdquo SAS Journal vol 4 no 4 pp 99ndash1062010

[90] D Avasthi Juxtafusional Outcomes with the Dynamic PosteriorLumbar InstrumentationWorld Spine III Rio de Jeneiro Brasil2005

[91] L Zhang X Shu Y Duan G Ye and A Jin ldquoEffectivenessof ISOBAR TTL semi-rigid dynamic stabilization system intreatment of lumbar degenerative diseaserdquo Zhongguo Xiu FuChong Jian Wai Ke Za Zhi vol 26 no 9 pp 1066ndash1070 2012

[92] S N Sangiorgio H Sheikh S L Borkowski L Khoo C RWarren and E Ebramzadeh ldquoComparison of three posteriordynamic stabilization devicesrdquo Spine vol 36 no 19 pp E1251ndashE1258 2011

[93] J D Coe S H Kitchel H J Meisel C H Wingo S E Leeand T-A Jahng ldquoNFlex dynamic stabilization system two-year clinical outcomes of multi-center studyrdquo Journal of KoreanNeurosurgical Society vol 51 no 6 pp 343ndash349 2012

[94] A Reyes-Sanchez B Zarate-Kalfopulos I Ramırez-Mora LMRosales-Olivarez A Alpizar-Aguirre and G Sanchez-BringasldquoPosterior dynamic stabilization of the lumbar spine with theAccuflex rod system as a stand-alone device experience in 20patients with 2-year follow-uprdquo European Spine Journal vol 19no 12 pp 2164ndash2170 2010

[95] M F Gornet F W Chan J C Coleman et al ldquoBiomechanicalassessment of a PEEK rod system for semi-rigid fixation of lum-bar fusion constructsrdquo Journal of Biomechanical Engineeringvol 133 no 8 Article ID 081009 2011

[96] D R Ormond L Albert Jr and K Das ldquoPolyetheretherketone(PEEK) rods in lumbar spine degenerative disease a case seriesrdquoJournal of Spinal Disorders amp Techniques 2012

[97] J J Yue G Malcolmon and J P Timm ldquoThe stabilimaxNZ posterior lumbar dynamic stabilization systemrdquo in MotionPreservation Surgery of the Spine J J Yu R Bertagnoli P CMcAfee and H S An Eds pp 476ndash482 Saunders ElsevierPress Philadelphia Pa USA 2008

[98] J J Yue J P Timm M M Panjabi and J Jaramillo-de la TorreldquoClinical application of the Panjabi neutral zone hypothesis theStabilimax NZ posterior lumbar dynamic stabilization systemrdquoNeurosurgical focus vol 22 no 1 p E12 2007

[99] L T Khoo L Pimenta and R Diaz ldquoTOPS total posteriorfacet replacement and dynamic motion segment stabilizationsystemrdquo in Motion Preservation Surgery of the Spine J J YuR Bertagnoli P C McAfee and H S An Eds pp 551ndash564Saunders Elsevier Press Philadelphia Pa USA 2008

[100] J Senegas ldquoMechanical supplementation by non-rigid fixationin degenerative intervertebral lumbar segments the wallissystemrdquo European Spine Journal vol 11 no 2 pp S164ndashS1692002

[101] KM Shibata and D H Kim ldquoHistorical review of Spinal artro-plasty and dynamic stabilizationrdquo inDynamic Reconstruction ofthe Spine D H Kim F P Cammisa Jr and R G Fessler Edspp 3ndash15ThiemeMedical Publishers NewYorkNYUSA 2006

[102] S M R Kabir S R Gupta and A T H Casey ldquoLumbarinterspinous spacers a systematic review of clinical and biome-chanical evidencerdquo Spine vol 35 no 25 pp E1499ndashE1506 2010

[103] Z Wan S Wang M Kozanek et al ldquoBiomechanical evaluationof the x-stop device for surgical treatment of lumbar spinalstenosisrdquo Journal of Spinal Disorders amp Techniques vol 25 no7 pp 374ndash378 2012

[104] J F Zucherman K Y Hsu C A Hartjen et al ldquoA multi-center prospective randomized trial evaluating the X STOPinterspinous process decompression system for the treatmentof neurogenic intermittent claudication two-year follow-upresultsrdquo Spine vol 30 no 12 pp 1351ndash1358 2005

Submit your manuscripts athttpwwwhindawicom

Stem CellsInternational

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


MEDIATORSINFLAMMATION

of


Behavioural Neurology

EndocrinologyInternational Journal of



Disease Markers


BioMed Research International

OncologyJournal of



Oxidative Medicine and Cellular Longevity


PPAR Research

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Immunology ResearchHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

ObesityJournal of



Computational and Mathematical Methods in Medicine

OphthalmologyJournal of


Diabetes ResearchJournal of



Research and TreatmentAIDS


Gastroenterology Research and Practice


Parkinsonrsquos Disease

Evidence-Based Complementary and Alternative Medicine

Volume 2014Hindawi Publishing Corporationhttpwwwhindawicom


results have not been obtained and lower back pain andcontinuous sciatica as high as 40 insisted [11ndash14] Insistinglow back pain and sciatica after discectomy procedures havebeen engaged to segmental instability and the concept ofchronic and degenerative instability has been suggested andthen developed within years [2 5ndash9] Some studies showedthat decompression with fusion (posterolateral or inter-body) meaningfully improved patient outcome compared todecompression alone [15ndash18] Fusion was carried out to ceasethe motion for stopping the pain in degenerative disordersof the lumbar spine [19] but every time the achievementcould not been arrived because to fuse the moving spinewas hard [20 21] Later internal fixation systems have beendiscovered by pioneers like Harrington Dick Magerl andRoy Camille and commonly used with fusion [22ndash24] Rigidpedicle screwfixation of spine improves the ratio of successfulfusions according to some biomechanical studies [25]

Rigid internal fixation and fusion have been currentlythe mainstay for surgical treatment of degenerative diseasesof the spine over the last 4 decades In all over the worldthe common experience was formed about fusion surgeryAlthough successful radiological results up to 100 associ-ated with fusion reported this results were not compatiblewith successful clinical outcome regarding pain alleviation[15 26 27] Satisfactory results of lumbar spinal fusion appearcompletely incompatible and ranged from 16 to 95with anaverage of 70 according to a meta-analysis study evaluatedsystematically [28] Rigid spinal implants along with fusionalso cause increased stresses of the adjacent segments andadjacent segment degeneration which is well known isformed [29ndash34] In addition fusion surgery has some impor-tant disadvantages such as donor site morbidity includingpain wound problems infections because of longer operatingtime pseudarthrosis and fatigue failure of implants [35ndash38]

The search for alternative spinal implants was supportedwith time on unsatisfactory outcomes of rigid internalfixation along with fusion The main aim was to avoidthe opposed effects of rigid implants on the stabilized andadjacent segments to prevent the implant failure and toprovide reduced-stress shielding and finally to develop asystem that permits increased load sharing and controlledmotion without cutting off the stability [39] Intervertebraldisc actually has a isotropic architecture like a fluid-filledball but it changes as intervertebral disc is degeneratedIsotropic properties and load transmission of the interverte-bral disc alter depending on disc degeneration [40 41] Theldquostone-in-the-shoerdquo phenomenon explains the postural painpattern in patients suffering from lumbar disc degenerationbecause pattern of loading is related to pain generation inthe degenerated spine which alters one patient to another[41 42] Dynamic stabilization intends to eliminate thepain by delivering the weight with more physiological loadtransmission between anterior and posterior components ofthe spine while attempting to maintain the motion and tocontrol abnormal movement in the spinal segment [42 43](Figure 1) It is supposed that soft or semirigid stabilizationsystems restore normal functions of the spine unit and protectthe adjacent segments [43 44]Dynamic stabilization of spinehas been classified by several authors [4 45 46] Today in

Figure 1 Posterior dynamic stabilization provides more physiolog-ical load transmission between anterior and posterior componentsof the spine

Figure 2 Cosmic posterior dynamic system

market different both anterior and posterior dynamic stabi-lization devices of spine are found Various biomechanicaland clinical studies were done about dynamic stabilizationsystems of spine Recently finite element studies have begunmore and more on these systems Some clinical studiesconcerning dynamic screws and dynamic rods have beenrevealed [37 44 47ndash49] Recently it is thought how we cando the dynamic stabilization systems which is close to morephysiological pattern

2 Indications of DynamicStabilization of Spine

Strempel et al revealed the indications for dynamic stabi-lization with cosmic (semirigid posterior dynamic systemincluding dynamic screw and rigid rod) [50] (Figure 2)These are symptomatic lumbar stenosis chronically recurrent











































































7 Conclusion





References




















































































































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of


























































































7 Conclusion





References




















































































































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of
























































































































of






Disease Markers



OncologyJournal of





PPAR Research



Journal of

ObesityJournal of
















review article dynamic stabilization for challenging...

Documents