L5–S1 disc replacement after two previous fusion surgeries for scoliosis

摘要

OpenimageinnewwindowFollowingscoliosissurgery,lumbarmotionsegmentdegenerationbelowtheleveloffusionisnotuncommon.Especiallylongfusionsextendingtothemidandlowerlumbarspineincreasethelikelihoodofdegenerationoftheremainingmotionsegments.Themanagementforthesepatientsiscontroversialanddependsontheclinicalpresentationandlevelofdegeneration.Theincreasingconfidenceinmotion-preservingtechnologyleadstoadilemmaonwhethertofusetheremaininglumbarlevelsorriskutilisingdiscarthroplastytopreservetheremainingmotionsegmentsandfacilitatecoronalbalanceinpatientswithpreviouslongfusionforscoliosis.Wepresentaninterestingcaseofa44-year-oldlady,whounderwenttwo-stagecorrectivesurgeryforprogressiveidiopathicscoliosisattheageof22?years.Inthefirststage,shehadT11–L3anteriorfusion,whilstinthesecondstageposteriorfusionwasdonefromT5toL3.At22?yearsaftertheinitialsurgery,shepresentedwithworseninglowbackpainandbilateralL4radicularsymptoms.MRIscanconfirmedseverediscdegenerationatL3–4andL5–S1levelswithpreservedL4–5disc.SheinitiallyunderwentL3–L4decompressionandposterolateralfusionatthatlevel,whichrelievedherradicularsymptoms.However,shehadpersistentpainatthelumbosacraljunctionwithModicIchanges.TheoptionsofananteriorL5–S1fusionordiscreplacementwereconsideredanddiscussedwiththepatient.Thediscreplacementoptionwasdecideduponwiththepatient,asanteriorfusionwasjudgedtoincreasetheriskofcoronalimbalance.Atthe1-yearfollow-up,shereportedsignificantimprovementinthebackpain.Theradiographsat1?yearshowedsatisfactorypositionandfunctionoftheartificialdiscreplacement.Thediscwasflexedlaterally,accommodatingthecoronalbalanceofthespine.WeconcludethatL5–S1motionsegmentcanbepreservedwithartificialdiscreplacementinpatientswithpreviouslongfusionforscoliosissurgery.Therealdifficultyariseswhenchoosingbetweendiscreplacementandextensionoffusion.Inourpatient,thediscreplacementhasworkedwellsofar.However,thediscisclearlyatamechanicaldisadvantage,andlossoffunctioninthemid-orlongtermwouldnotbesurprising...