OPLL颈椎后纵韧带骨化课件

OPLL经典综述讲读Ossificationoftheposteriorlongitudinalligament(OPLL)resultsfrompathologicreplacementofthePLLwithlamellarbone,potentiallycausingspinalcordcompressionandneurologicdeteriorationOPLLwasfirstdescribedinJapanesepatientsandhasclassicallybeenconsideredacauseofmyelopathyinpatientsofEastAsianoriginspondylosismyelopathyradiculopathystenosisdischerniationPathoanatomyThePLLrunsalongthedorsalsurfaceoftheC1anteriorarchandcervicalvertebralbodiesandconsistsoflongitudinalfibersconfluentwiththetectorialmembranecraniallyandendingatthesacrumcaudallyfunctionally,thePLLresistsspinehyperflexionNaturalHistoryPatientswithOPLLcommonlypresentintheirfifthandsixthdecades,withmenaffectedtwiceasoftenaswomen.Mostpatientshavesomeneurologicsymptomsatdiagnosis,with28%to39%fulfillingdiagnosticcriteriaformyelopathyInpatientswithmyelopathy,64%haddeteriorated,however,and89%ofpatientswithNurickgrade3or4myelopathywhorefusedsurgeryhadprogressedtoawheelchair-orbed-boundstateRiskfactorsforthedevelopmentofmyelopathyinclude＞60%spinalcanalstenosis,＜6mmofspaceavailableforthecord,increasedcervicalrangeofmotion,andOPLLthatislaterallydeviatedwithinthespinalcanalAge,gender,andthenumberoflevelsaffectedbyOPLLdonotaffecttheprognosisClinicalPresentationChangesingaitorbalance,lossoffinemotorcontrol,andupperextremityweakness,numbness,orparesthesiasaresuggestiveofmyelopathyEarlymuscularfatigueorworseningsymptomsattheextremesofcervicalmotionarealsoconcerningPhysicalExaminationRadiologicEvaluationCTwithsagittalandcoronalreformattinghasemergedasthebenchmarkforradiographicevaluationofOPLLandisnecessarytoreliablycharacterizeitNonsurgicalManagementProphylacticsurgeryisneithernecessarynorrecommendedManagementincludestemporaryimmobilizationwithaneckbrace,steroidalornonsteroidalanti-inflammatorymedications,activitymodification,andphysicaltherapypatientsshouldbeadvisedtoavoidactivitiesthatmayresultinsuddenorexcessivecervicalspinemotionbecauseOPLLisassociatedwithahighrateofacutespinalcordinjury,eveninpatientswhodonotmeetsurgicalcriteriaAnteriorDecompressionandFusionProponentsarguethatitallowsforasuperiordecompressionandismoreeffectiveatmaintainingorrestoringcervicallordosisthanisposteriorsurgery.Associatedanteriorpathology,suchasdiskherniations,canalsobeaddressedDisadvantagesincludetechnicaldifficulty,inabilitytodecompresscranialtoC2,andhighratesofpseudarthrosisanddysphagiawhenthreeormorelevelsrequiretreatmentDuraltearsarealsomuchmorecommonwithananteriorapproach,giventhatanteriorduralossificationoccursin13%to15%ExposureisprovidedbythestandardSmith-Robinsonapproach,anddiskectomy,hemicorpectomy,orsubtotalcorpectomysufficienttoallowexposureoftheunderlyingOPLLmassisperformedCorpectomiesofuptofivelevelshavebeenperformedwithsuccess,butremovalofthreeormorecontiguouslevelsisassociatedwithincreasedcomplicationandreoperationratesComplicationsoccuraspartoftheapproach(eg,dysphagia,dysphonia),thedecompression(eg,C5palsy,duraltears),orthefusion(eg,graftsubsidence,pseudarthrosis)Nerverootpalsiesoccurin4%to17%ofpatientsthrougheitherdirecttraumaortraction.Patientspresentwithweakness,numbness,pain,orparesthesias,mostcommonlyintheC5distributionDuraltearsoccurin4%to20%ofpatients,oftenbecauseofduralossificationorattenuation.Cerebrospinalfluidleakagemayresultinpseudomeningoceleorfistulaformation,leadingtoneuraldamage,airwaycompression,meningitis,orwoundcomplicationsTearsrecognizedintraoperativelyaretreatedbydirectrepairorbyapplicationofautogenousfascialorsyntheticcollagengrafts.Closureofpinholedefectsoraugmentationofrepairsisdonewiththrombogenicsealants,suchasfibringlueorgelatinfoam.Postoperatively,divertinglumbardrainsandbedrestcanbeusedInanefforttoreduceduraltearrates,Yamauraetalintroducedthe“anteriorfloatingmethod”forcervicaldecompression,consistingofsubtotalvertebralbodyresectionandthinning,butnotremoval,oftheOPLL.Theposteriorvertebralbodyisnotreconstructed,allowingtheOPLLto“float”anteriorlyandawayfromthespinalcanal.At5-yearfollow-up,theauthorsachievedameanrecoveryrateof68.5%andimprovementinJapaneseOrthopaedicAssociationscoresfrom8.3to14.2.Noleaksofcerebrospinalfluidoccurred,but14%ofpatientswereleftwithaninadequatedecompression.Inthesepatients,orwithOPLLprogression,theauthorsrecommendedsubsequentposteriordecompression.Whenaddressingmorethantwoorthreelevels,fibularstrutgraftsarepreferredfortheirstructuralsupport.Foroneortwolevels,structuralgraftsoftricorticaliliaccrest,fibula,andvertebralbodieshaveallbeendescribed.Morerecently,interbodycageswithnonstructuralbonegraftorbonegraftsubstituteshavebeenused.Overallratesofpseudarthrosisvaryfrom3%to15%,withthehighestratesoccurringinpatientsundergoingfusionofthreeormorelevels.PosteriorDecompressionWhenmorethantwoorthreecervicallevelsareaffectedbyOPLL,posteriorsurgery(ie,laminoplasty,orlaminectomyandfusion)ispreferredbecauseofthetechnicaleaseandlowerrateofcomplications.Disadvantagesincludetheriskofpostoperativediseaseprogression,inabilitytocorrectcervicalkyphosis,andpoorresultsinK-linenegativepatients.Laminoplastyaccomplishesthisbyhingingopenthelaminaewitheitheran“opendoor”or“Frenchdoor”technique,resultingina30%to40%increaseinthesizeofthespinalcanalLaminectomyandfusionentailsremovalofthelaminaefollowedbyinstrumentedposterolateralfusion,resultingina70%to80%increaseincanalvolumeAfullanalysisoftheadvantagesanddisadvantagesbetweenlaminoplastycomparedwithlaminectomyandfusionhasbeendiscussedelsewhereOurpreferenceistouselaminectomyandfusionforOPLLbecausetheretainedcervicalmotionwithlaminoplastymayallowdiseaseprogression,andtheriskforprogressiontokyphosisattheaffectedlevelsiseliminatedwithfusionForseveredisease,recoveryratesafterposteriordecompressionappeartobelowerthanthosefollowinganteriordecompression,butwithalowercomplicationrateIwasakietalretrospectivelycomparedtheresultsofanteriordecompressionandfusionwiththoseoflaminoplasty;theyreportedbetteroutcomesafteranteriorsurgeryinpatientswithanOPLLmassoccupying＞60%ofthecanal;however,itresultsinareoperationrateof26%versus2%inthelaminoplastygroup.With＜60%canaloccupancy,recoveryrateswereequivalent.Aprospectivecomparisonofanteriordecompressionandfusionversuslaminoplastyfoundsimilarresults.Patientswith＞50%canaloccupancyhadsuperiorrecoveryrateswithanteriorsurgerybutequivalentrateswith＜50%involvementPatientswith＜5°ofcervicallordosisalsohadsignificantlyworseoutcomesfromlaminoplasty,and50%lostlordosisversusnoneinthefusiongroup.HalfofthelaminoplastypatientsexperiencedOPLLprogressionversusonlyoneafteranteriorsurgeryHowever,surgicalcomplicationsheavilyfavoredlaminoplasty,witha23%complicationrateanda14%reoperationrateintheanteriorgroupandnoneinthelaminoplastypatientsOnlyonestudytodatehasexaminedtheresultsoflaminectomyandfusionforOPLL.Chenetalreportedameanrecoveryrateof62%at5yearsamong83patientswhounderwentinstrumentedlaminectomyandfusionfromC2orC3toC7.Patientswithagoodoutcomehadsignificantlymorepostoperativelordosis(16.1°versus10.4°).Nootherfactors,includingoccupyingratio,weresignificantbetweengroups.Thereoperationratewas4%,alltheresultofepiduralhematomaformation.Whetherposteriorfusionhadaneffectondiseaseprogressionwasnotevaluated,althoughtheauthorsnotednolongtermdeclineinneurologicrecovery,asiscommonlyseeninlaminoplastypatients.Themostcommoncomplicationofposteriorsurgeryislowcervicalnerverootpalsy,whichoccursin4%to12%ofpatients.Injurymayoccurfromdirect