ThoracolumbarThoracolumbar andand LumbarLumbar BurstBurst FracturesFractures

SussanSussan Salas,Salas, MDMD ThomasThomas JeffersonJefferson UniversityUniversity HospitalHospital DepartmentDepartment ofof NeurologicalNeurological SurgerySurgery ThoracolumbarThoracolumbar/Lumbar/Lumbar BurstBurst Fractures:Fractures: OverviewOverview

„ EpidemiologyEpidemiology „ AnatomyAnatomy „ InitialInitial AssessmentAssessment „ ImagingImaging „ InjuryInjury Mechanism/BiomechanicsMechanism/Biomechanics „ FractureFracture ClassificationClassification „ TreatmentTreatment Options:Options: OperativeOperative vs.vs. NonNon-- operativeoperative ManagementManagement EpidemiologyEpidemiology

„ 79,00079,000 spinalspinal fracturesfractures inin U.S.U.S. eacheach yearyear –– 72.5%72.5% involveinvolve thoracicthoracic oror lumbarlumbar spinespine [1,2] „ MostMost commoncommon sitesite ofof injuryinjury isis thoracolumbarthoracolumbar junctionjunction „ MechanicalMechanical transitiontransition zonezone betweenbetween rigidrigid thoracicthoracic andand moremore mobilemobile lumbarlumbar spinespine [3-5]

„ LumbarLumbar spinespine moremore proneprone toto injuryinjury „ Absence of ribs, transition from kyphotic to lordotic posture, sagitally oriented facet joints [6]

„ OperativeOperative versusversus nonnon--operativeoperative mgmt:mgmt: controversycontroversy AnatomyAnatomy

„ Vertebral column: 29 vertebrae organized in 4 curves: „ 2 primary curves present at birth: thoracic and sacral (kyphosis) „ 2 compensatory curves - result of adaptation to upright posture: cervical and lumbar (lordosis) AnatomyAnatomy

„ T spine: made rigid by ribcage articulations (ligamentous support); facet joints in coronal plane limit flexion/extension „ L spine: facet joints in sagittal plane increase flexion/extension but decrease lateral bending/rotation „ TL junction: facet joints in oblique orientation; provide support and resistance to 35-45% of torsional and shear forces on spine InitialInitial AssessmentAssessment „ ABCsABCs && ImmobilizationImmobilization:: patientspatients shouldshould bebe immobilizedimmobilized untiluntil stabilitystability ofof fracturefracture cancan bebe assessedassessed adequatelyadequately –– avoidavoid loss/worseningloss/worsening ofof neurologicalneurological deficitsdeficits [4] „ NeurologicalNeurological examexam:: performedperformed asas soonsoon asas thethe patientpatient isis hemodynamicallyhemodynamically stable:stable: motor,motor, sensation,sensation, DTRsDTRs,, digitaldigital rectalrectal examexam [10] „ NeurologicNeurologic deficitsdeficits fromfrom TLTL fxsfxs cancan involveinvolve spinalspinal cordcord oror caudacauda equinaequina „ 70%70% ofof thoracolumbarthoracolumbar injuriesinjuries dodo notnot havehave associatedassociated neurologicneurologic deficitsdeficits [2] InitialInitial Assessment:Assessment: Motor Examination „ Upper extremity „ C5-shoulder abduction „ C6-wrist extension „ C7-wrist flexion „ C8-finger flexion „ T1-finger abduction InitialInitial Assessment:Assessment: Motor Examination

„ Lower extremity „ L1-hip flexion „ L2-hip adduction „ L3-knee extension „ L4-ankle dorsiflexion „ L5-toe extension InitialInitial Assessment:Assessment: DermatomesDermatomes InitialInitial Assessment:Assessment: Classification of injury

„ American Spinal Injury Association (ASIA) „ A = Complete – No Sacral Motor / Sensory „ B = Incomplete – Sacral sensory sparing „ C = Incomplete – Motor Sparing (<3) „ D = Incomplete – Motor Sparing (>3) „ E = Normal Motor & Sensory E Imaging:Imaging: XX--RaysRays

„ APAP andand laterallateral:: „ APAP view:view: pedicles,pedicles, VBsVBs,, discdisc spaces,spaces, spinousspinous processesprocesses „ LateralLateral view:view: VBVB heights,heights, discdisc spacespace relations,relations, VBVB alignment,alignment, paraspinalparaspinal swellingswelling Imaging:Imaging: XX--rayray

„ InIn thethe presencepresence ofof injury,injury, thethe entireentire spinespine shouldshould bebe imagedimaged toto rulerule outout noncontiguousnoncontiguous injuriesinjuries „ DegreeDegree ofof kyphosiskyphosis cancan bebe measuredmeasured usingusing CobbCobb Measurement.Measurement. Imaging:Imaging: CTCT

„ CTCT yieldsyields moremore diagnosticdiagnostic informationinformation thanthan plainplain radiographsradiographs regardingregarding extentextent ofof bonybony injuryinjury [6,12] Imaging:Imaging: MRIMRI

„ MRIMRI allowsallows visualizationvisualization ofof softsoft tissuetissue componentscomponents ofof spinalspinal injuriesinjuries [6] „ UsefulUseful atat thoracothoraco-- lumbarlumbar junctionjunction duedue toto variablevariable locationlocation ofof conusconus medullarismedullaris InjuryInjury Mechanism/BiomechanicsMechanism/Biomechanics

„ GravityGravity exertsexerts continualcontinual axialaxial loadload onon thethe vertebralvertebral columncolumn „ BodyBody’’ss centercenter ofof gravitygravity isis approxapprox 4cm4cm anterioranterior toto firstfirst sacralsacral vertebravertebra –– resultsresults inin ventralventral bendingbending vectorvector actingacting onon spinalspinal columncolumn „ PosteriorPosterior ligamentousligamentous complexcomplex actsacts asas dorsaldorsal tensiontension bandband toto counteractcounteract thesethese forcesforces -- netnet sumsum ofof vectorsvectors actingacting onon spinespine equalequal zerozero „ EssentialEssential toto preventprevent changechange inin spinespine’’ss sagittalsagittal alignmentalignment InjuryInjury Mechanism/BiomechanicsMechanism/Biomechanics „ PLCPLC:: interspinousinterspinous ligamentsligaments andand ligamentumligamentum flavumflavum „ TraumaTrauma resultingresulting inin spinalspinal ligament/osseousligament/osseous structurestructure disruptiondisruption maymay changechange netnet vectorvector sumsum actingacting onon spinespine fromfrom zero,zero, resultingresulting inin potentialpotential forfor spinalspinal imbalanceimbalance InjuryInjury Mechanism/BiomechanicsMechanism/Biomechanics „ WhitesideWhiteside [9]:: analogyanalogy ofof constructionconstruction cranecrane „ FailureFailure ofof thethe cablecable leadsleads toto thethe cranecrane fallingfalling forwardforward –– inin spine,spine, illustratedillustrated byby characteristiccharacteristic kyphotickyphotic deformitydeformity seenseen withwith unstableunstable burstburst fxsfxs FractureFracture ClassificationClassification

„ FractureFracture classificationclassification allowsallows organizationorganization andand treatmenttreatment ofof fracturesfractures throughthrough protocolsprotocols developeddeveloped toto maximizemaximize patientpatient outcomesoutcomes

„ MostMost classificationclassification schemesschemes basedbased onon criteriacriteria forfor describingdescribing stabilitystability FractureFracture Classification:Classification: HoldsworthHoldsworth

„ HoldsworthHoldsworth [15]: twotwo--columncolumn modelmodel ofof spinespine stabilitystability (1960s).(1960s). SeparatedSeparated spinespine intointo anterioranterior weightweight--bearingbearing columncolumn (a)(a) andand posteriorposterior tensiontension--bearingbearing columncolumn (b)(b) „ BurstBurst fracturesfractures unstableunstable ifif PLCPLC isis disrupteddisrupted FractureFracture Classification:Classification: DenisDenis

„ DenisDenis [3]:[3]: threethree--columncolumn classificationclassification ofof spinalspinal fracturesfractures (1980s).(1980s). InjuryInjury toto middlemiddle columncolumn waswas necessarynecessary andand sufficientsufficient toto createcreate instabilityinstability „ BasedBased classificationclassification onon resultsresults ofof biomechanicalbiomechanical studiesstudies demonstratingdemonstrating thatthat isolatedisolated rupturerupture ofof PLCPLC isis insufficientinsufficient toto createcreate instabilityinstability FractureFracture Classification:Classification: DenisDenis

„ DividesDivides spinalspinal fracturesfractures intointo minorminor andand majormajor injuriesinjuries „ MinorMinor injuries:injuries: fracturesfractures ofof transversetransverse process,process, parspars interarticularisinterarticularis,, spinousspinous processprocess „ MajorMajor injuries:injuries: Fracture type Column Anterior Middle Posterior Compression Compression Intact Intact , or distraction Burst Compression Compression Intact Seat-belt type Intact Distraction Fracture Compression, Distraction , rotation , shear dislocation rotation , shear FractureFracture Classification:Classification: DenisDenis

„ CompressionCompression FractureFracture „ BurstBurst FractureFracture FractureFracture Classification:Classification: DenisDenis

„ SeatSeat--beltbelt typetype „ FractureFracture dislocationdislocation FractureFracture Classification:Classification: DenisDenis „ DenisDenis’’ 33 typestypes ofof instability:instability: „ MechanicalMechanical (1(1st degree)degree) –– maymay resultresult inin latelate kyphotickyphotic deformity.deformity. RequireRequire externalexternal oror operativeoperative stabilization.stabilization. „ NeurologicNeurologic (2(2nd degree)degree) –– retropulsionretropulsion ofof bonebone fragmentsfragments predisposepredispose patientspatients toto increasedincreased riskrisk forfor neurologicneurologic injury.injury. ControversyControversy re:re: operativeoperative stabilization.stabilization. „ Mechanical/neurologicMechanical/neurologic (3(3rd degree)degree) –– developdevelop afterafter burstburst fxfx w/neurow/neuro deficitdeficit oror fracture/dislocation.fracture/dislocation. HighlyHighly unstableunstable >> requirerequire operativeoperative decompressiondecompression andand stabilization.stabilization. FractureFracture Classification:Classification: McCormackMcCormack „ McCormackMcCormack [17]:: loadload--sharingsharing classification,classification, designeddesigned specificallyspecifically forfor thoracolumbarthoracolumbar burstburst fxsfxs (1994)(1994) „ UsesUses pointpoint system:system: gradesgrades amountamount ofof VBVB comminutioncomminution,, displacementdisplacement ofof fracturefracture fragments,fragments, degreedegree ofof kyphosiskyphosis (1(1--99 points)points)

Score 1 point 2 points 3 points Sagittal collapse 30% >30% 60% Shift 1mm 2mm >2mm Correction 3 degrees 9 degrees 10 degrees FractureFracture Classification:Classification: McCormackMcCormack „ WithWith McCormack,McCormack, patientspatients withwith >6>6 pointspoints havehave aa largelarge voidvoid oror gap,gap, resultingresulting inin leastleast supportivesupportive anterioranterior andand middlemiddle columnscolumns andand predisposingpredisposing posteriorposterior instrumentationinstrumentation forfor failurefailure

„ OriginalOriginal goalgoal waswas toto predictpredict failurefailure ofof shortshort-- segmentsegment posteriorposterior fixationfixation forfor burstburst fxsfxs –– prescribesprescribes thatthat injuriesinjuries withwith highhigh scoresscores shouldshould undergoundergo supplementalsupplemental anterioranterior columncolumn supportsupport FractureFracture Classification:Classification: TLICSTLICS Injury morphology [13] „ TLICSTLICS systemsystem Compression 1 designeddesigned byby thethe SpineSpine Burst 1 TraumaTrauma StudyStudy GroupGroup Translation rotation 3 Distraction 4 (2008).(2008). BasedBased onon 33 PLC integrity aspects:aspects: Intact 0 „ morphologymorphology ofof thethe injuryinjury Indeterminate 2 Disrupted 3 „ integrityintegrity ofof thethe PLCPLC Neurological status „ neurologicalneurological statusstatus ofof thethe Intact 0 patientpatient Nerve root injury 2 Complete 2 Incomplete 3 FractureFracture Classification:Classification: TLICSTLICS

„ TLICSTLICS determinationdetermination forfor surgery:surgery: „ <3<3 pointspoints cancan bebe treatedtreated nonnon--operativelyoperatively „ >5>5 pointspoints usuallyusually requirerequire surgicalsurgical interventionintervention „ == 44 pointspoints cancan bebe treatedtreated w/orw/or w/ow/o surgerysurgery „ TLICSTLICS determinationdetermination ofof surgicalsurgical approach:approach: „ IncompleteIncomplete ++ anterioranterior compressioncompression == ANTANT „ IncompetentIncompetent PLCPLC == POSTPOST „ NeurologicalNeurological deficitdeficit ++ incompetentincompetent PLCPLC == ANTANT ++ POSTPOST TreatmentTreatment OptionsOptions

„ ControversyControversy regardingregarding operativeoperative vs.vs. nonnon-- operativeoperative management,management, surgicalsurgical approachapproach

„ TreatmentTreatment basedbased onon maximizingmaximizing neurologicneurologic recoveryrecovery andand preventingpreventing neurologicneurologic declinedecline –– identifyidentify unstableunstable fracturesfractures NonNon--operativeoperative ManagementManagement

„ MostMost fracturesfractures inin thoracolumbarthoracolumbar/lumbar/lumbar regionregion consistconsist ofof compression,compression, burstburst fractures,fractures, andand isolatedisolated dorsaldorsal columncolumn fracturesfractures –– stablestable fxsfxs „ CompressionCompression fxsfxs:: stablestable ifif PLC,PLC, alongalong withwith dorsaldorsal vertebralvertebral body,body, isis notnot disrupteddisrupted (Denis)(Denis) –– bracingbracing „ BurstBurst fxsfxs:: stablestable ifif nono PLCPLC injury/dorsalinjury/dorsal elementelement fxfx.. NeurologicallyNeurologically intactintact patientpatient >> bracingbracing NonNon--operativeoperative ManagementManagement MumfordMumford etet alal

„ 4141 ptspts withwith thoracothoraco--lumbarlumbar burstburst fxsfxs w/ow/o neurologicalneurological deficitdeficit treatedtreated conservativelyconservatively „ AtAt injury,injury, canalcanal compromisecompromise averagedaveraged 37%37% -- atat 22 yearsyears f/uf/u,, 2/32/3 resolutionresolution ofof fragmentsfragments occludingoccluding canalcanal „ OutcomeOutcome evaluation:evaluation: 49%49% patientspatients reportedreported excellentexcellent outcomesoutcomes relativerelative toto painpain andand functionfunction „ ProgressionProgression ofof bodybody collapsecollapse onon imagingimaging averagedaveraged 8%8% „ 11 ptpt developeddeveloped neurologicneurologic deteriorationdeterioration promptingprompting surgerysurgery –– allall otherother ptspts remainedremained neurologicallyneurologically intactintact NonNon--operativeoperative ManagementManagement CantorCantor etet alal „ 1818 neurologicallyneurologically intactintact patientspatients withwith burstburst fxsfxs w/ow/o PLCPLC disruptiondisruption –– treatedtreated withwith earlyearly ambulationambulation w/bracingw/bracing „ KyphosisKyphosis:: 1919 degreesdegrees atat timetime ofof injury,injury, 2020 degreesdegrees atat f/uf/u „ VBVB heightheight loss:loss: 36%36% onon presentation,presentation, maxmax changechange 5%5% atat f/uf/u „ AtAt f/u15f/u15 ptspts ratedrated theirtheir painpain asas littlelittle oror none,none, 1717 ptspts hadhad littlelittle oror nono restrictionrestriction ofof activity.activity. „ CTCT scanscan 11 yryr afterafter injuryinjury inin 88 ptspts showedshowed >50%>50% resorptionresorption ofof retropulsedretropulsed bonebone „ NoNo patientpatient hadhad deteriorationdeterioration ofof neurologicalneurological function.function. SurgicalSurgical TreatmentTreatment

„ SurgicalSurgical TreatmentTreatment –– 33 components:components: „ NeuralNeural DecompressionDecompression „ StabilizationStabilization „ FusionFusion SurgicalSurgical treatment:treatment: DecompressionDecompression

„ TLTL andand LspineLspine fxfx w/w/ neuroneuro deficitdeficit havehave significantlysignificantly higherhigher recoveryrecovery raterate whenwhen treatedtreated withwith surgery.surgery. PrimaryPrimary goal:goal: decompressiondecompression ofof thethe spinalspinal canalcanal [4,7] „ Anterior,Anterior, comparedcompared toto posteriorposterior andand posterolateralposterolateral decompressiondecompression hashas aa higherhigher raterate ofof neurologicneurologic improvementimprovement (88%(88% vs.vs. 64%)64%) andand recoveryrecovery ofof B&BB&B functionfunction (69%(69% vs.vs. 33%).33%).[8,18] „ AnteriorAnterior decompressiondecompression viavia corpectomycorpectomy:: maximalmaximal degreedegree ofof canalcanal decompressiondecompression „ TreatmentTreatment ofof lowlow lumbarlumbar (L3(L3--5)5) burstburst fxfx requirerequire posteriorposterior approachapproach SurgicalSurgical treatment:treatment: DecompressionDecompression

„ TimingTiming ofof surgerysurgery inin patientspatients w/burstw/burst fxsfxs w/neurologicw/neurologic deficitdeficit isis unclearunclear „ MostMost clinicalclinical studiesstudies havehave shownshown nono correlationcorrelation b/wb/w timingtiming andand amountamount ofof neurologicneurologic recoveryrecovery [7,11] „ OneOne studystudy ((MirzaMirza etet al,al, 1999)1999) showedshowed improvedimproved neurologicneurologic recoveryrecovery w/surgeryw/surgery withinwithin 7272 hrshrs vs.vs. 1010-- 1414 daysdays [16] „ PatientsPatients w/progressivew/progressive deficitdeficit needneed emergentemergent decompressiondecompression SurgicalSurgical Treatment:Treatment: StabilizationStabilization

„ PrimaryPrimary rolerole ofof surgicalsurgical instrumentation:instrumentation: restorerestore immediateimmediate stabilitystability andand correctcorrect acuteacute deformitiesdeformities „ AnteriorAnterior stabilization:stabilization: „ Advantage:Advantage: limitslimits fusionfusion toto levellevel aboveabove andand belowbelow injuryinjury „ Disadvantage:Disadvantage: riskrisk ofof vascularvascular andand visceralvisceral injuryinjury SurgicalSurgical Treatment:Treatment: StabilizationStabilization „ OptionsOptions forfor posteriorposterior stabilization:stabilization: rodsrods securedsecured byby screws,screws, hooks,hooks, oror wireswires „ PediclePedicle screwscrew system:system: instrumentinstrument twotwo levelslevels aboveabove andand belowbelow injuryinjury „ ShortShort segmentsegment stabilizationstabilization (one(one levellevel aboveabove andand below)below) hashas highhigh raterate ofof constructconstruct failure.failure. IfIf spinalspinal flexibilityflexibility isis priority,priority, cancan bebe combinedcombined w/anteriorw/anterior instrumentationinstrumentation [17,19] SurgicalSurgical Treatment:Treatment: FusionFusion „ LongLong termterm goalgoal ofof instrumentation:instrumentation: maintainmaintain properproper spinalspinal alignmentalignment andand stabilitystability untiluntil bonebone fusionfusion occursoccurs [9,19] „ WithoutWithout solidsolid fusion,fusion, metallicmetallic implantsimplants eventuallyeventually breakbreak „ InIn orderorder forfor fusionfusion toto occur,occur, bonebone graftgraft oror graftgraft replacementreplacement mustmust have:have: „ OsteogenicityOsteogenicity „ OsteoinductivityOsteoinductivity „ OsteoconductivityOsteoconductivity SurgicalSurgical Treatment:Treatment: FusionFusion „ AnteriorAnterior fusion:fusion: „ AutograftAutograft (Iliac(Iliac crest)crest) „ AllograftAllograft (Femoral(Femoral oror humeralhumeral shaft)shaft) „ SyntheticSynthetic cagecage „ PosteriorPosterior fusion:fusion: „ DecorticationDecortication ofof exposedexposed bonebone elementselements „ ImplantationImplantation ofof bonebone fragmentfragment oror bonebone matrixmatrix ThoracolumbarThoracolumbar/Lumbar/Lumbar BurstBurst Fractures:Fractures: OverviewOverview

„ EpidemiologyEpidemiology „ AnatomyAnatomy „ InitialInitial AssessmentAssessment „ ImagingImaging „ InjuryInjury Mechanism/BiomechanicsMechanism/Biomechanics „ FractureFracture ClassificationClassification „ TreatmentTreatment Options:Options: OperativeOperative vs.vs. NonNon-- operativeoperative ManagementManagement ReferencesReferences

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„ [11] Bradford DS, Akbarnia BA, Winter RB, et al. Surgical stabilization of fracture and fracture dislocations of the thoracic spine. Spine. 1977;2:185–96. „ [12] McCulloch PT, France J, Jones DL, et al. Helical computer tomography alone compared with plain radiographs with adjunct computed tomography to evaluate the cervical spine after high-energy trauma. J Bone Joint Surg Am. 2005;87:2388–94. „ [13] Rihn JA, Anderson DT, Vaccaro A, et al. A review of the TLICS system: a novel, user- friendly thoracolumbar trauma classification system. Acta Orthopaedica 2008; 79 (4): 461-6. „ [14] Keenen TL, Anthony J, Benson DR. Dural tears associated with lumbar burst fractures. J Orthop Trauma. 1990;4:243–5. „ [15] Holdsworth FW. Fractures, dislocations and fracture-dislocations of the spine. J Bone Joint Surg Br. 1963;45:6–20. „ [16] Mirza SK, Krengel WF, Chapman JR, et al. Early versus delayed surgery for acute cervical spinal cord injury. Clin Orthop. 1999;359:104–14. „ [17] McCormack T, Karaikovic E, Gaines R. The load sharing classification of spine fractures. Spine. 1994;19:1741–44. „ [18] Gertzbein SD. Scoliosis Research Society: multicenter spine fracture study. Spine. 1992;17:528–40. „ [19] McLain RF, Sparling E, Benson DR. Early failure of short-segment pedicle instrumentation for thoracolumbar fractures: a preliminary report. J Bone Joint Surg Am. 1993;75:162–7