CBLO: another osteotomy procedure in the treatment of CCL ... Jarmo.pdf · Advantages of CBLO • More bone stock proximally, helpful especially in small breed dogs • Mechanical

CBLO:anotherosteotomyprocedureinthetreatmentofCCL

ruptureJarmoRintasalo,DVM

CORAprinciple

•  CoraBasedLevelingOsteotomy•  CenterofRotationofAngulation•  Methodtoanalyzeanddiagnosemalalignmentinlongbonesandplanfortheircorrectionbyosteotomy

Whyanotherosteotomy?

•  Manygoodtechniques– TPLO– TTA– TightRope– Lateralsuture–  Intra-articulargraft+augmentation

•  Notechniqueisperfect

Problemsw.currenttechniques

•  Continuedlaxity– 30%ofTPLO–  70%ofTTA

•  Latemeniscaltears•  Arthrosis•  Implantproblems•  Infections•  Tumors

RationaleforCBLO

•  AlterationoftibialaxiswithanosteotomyshouldoccurattheCORAtominimizeharmfuleffectsonjointmechanics

•  Tibiahasnormallyproximalprocurvatum,whichcausesTPAtobe23-25degrees

•  CBLOstraightensproximaltibialeaving8-12°ofpostoperativeTPA

RationaleforCBLO

•  TPLOcorrectsTPAto5-6degrees,whichmaybetoomuch–  cartilagewear–  upto14°isok

•  TTAeffect(advancement)–  tibialplateauat90°topatellatendon

AdvantagesofCBLO

•  Morebonestockproximally,helpfulespeciallyinsmallbreeddogs

•  Mechanicalaxiswillbeinsidethebone,notcaudaltoit,nobalconyeffect

•  Extra-articularosteotomy•  Auxiliaryfixationpossible(derangedstifle)•  Patellaluxationcorrectionwithtibialtuberositytranspositionpossible

AdvantagesofCBLO

•  Facilitateslevelinginadolescentpatientsavoidingopengrowthplates

•  FacilitatesprocedureindogswithTPA>34°•  DoublecutinextremeTPAslopes•  Facilitatescorrectionincaseswithcompromisedtibialcrest

PlanningStartbymeasuringTPA

PlanningJointorientationline

PlanningJointorientationlineProximalmetaphyseallineCranialslopeofintercondylareminencedistallyat0,35xTPA,normally8-12° 81°

PlanningJointorientationlineProximalmetaphyseallineProximaldiaphyseallineCenterofmedullarycavityatdistalendofcristatibaetotuberofGerdy

CORAlocationandmagnitude

CORA

MagnitudeofCORA

PlanningJointorientationlineProximalmetaphyseallineProximaldiaphyseallineBisectingline

AllpointsonthislinerepresenttheCORA

PlanningJointorientationlineProximalmetaphyseallineProximaldiaphyseallineBisectinglineSawbladesizeandorientation

perpendiculartocaudalcortexmeetscranialcortexcenteredonbisectingline

PlanningJointorientationlineProximalmetaphyseallineProximaldiaphyseallineBisectinglineSawbladesizeandorientationAmountoftransferfromchartorcalculation

2πr=360

D1D2

Stabilization

•  CBLOplate,lockingscrews– VOI,Fixin

•  TPLOplate•  T-plate•  Additionalfixationtocounteractquadriceps– Compressionscrew– Pin&wire

Pitfalls

•  Rotationtendstocreatevalgusdeformity– Directionofsawcutimportant

•  Fibulamayinterferewithrotation– Fibularbending

•  Needforfixationagainstquadricepspull– Headlesscompressionscrew– Pin+wire

Wiiwi,lab6months

Wiiwi13months

Sulo,whippet

•  Avulsionofaclfromfemur•  DistalcutaroundCORA

avoidingproximalgrowthplate

•  FixationwithVIprototypelockingplate

Sulo6/10weekspostop