How to correct How to correct extraarticular deformity extraarticular deformity
without causing without causing instabilty ?instabilty ?
Jean-Louis BRIARDJean-Louis BRIARD
Intraarticular spaceIntraarticular space Extraarticular spaceExtraarticular space apart from the apart from the
"collateral ligament "collateral ligament frame"frame"
"bony" component of the deformity"bony" component of the deformity a major aspect in TKRa major aspect in TKR
Need for definitions !
Consider shape of the bones
+ +
(reference to the mechanical axis)
When performing a TKR:When performing a TKR: wellwell aligned in Neutral aligned in Neutral horizontal or perpendicular horizontal or perpendicular
joint line joint line
ie ie normo prosthetic femur & normo prosthetic femur & tibiatibia
stable & mobilestable & mobile
Well aligned kneesWell aligned knees
#1 Consider the orientation of the joint line
"SIMPLE""SIMPLE" Neutral alignmentNeutral alignment Femur ValgumFemur Valgum Tibia VarumTibia Varum
ie well alignedie well aligned
with with an oblique joint linean oblique joint line
FEW PRINCIPLES
but you want an but you want an horizontal joint linehorizontal joint linein Extension:in Extension: resect more medial condyleresect more medial condyle more lateral plateaumore lateral plateauChange anatomical femur valgum in Change anatomical femur valgum in prosthetic normo prosthetic normo
femurfemurAnatomical tibia varum in Anatomical tibia varum in protheticprothetic normo tibianormo tibia
