in flexion:in flexion: released, elongated released, elongated

LCL may be weakLCL may be weak

(danger of instability)(danger of instability) Rotate the femoral Rotate the femoral

implant in exagerated implant in exagerated ER ER to be stableto be stable

NB: due to the release:

tibial cut & Trans Epicondylar Axis are not even // !

think of think of lateral lateral condyle condyle osteotomyosteotomy to to have strong have strong lateral structures lateral structures at the right lengthat the right length

Lateral collateral ligament release(saving popliteus tendon)

PP

2nd MESSAGE2nd MESSAGE

MEDIAL RELEASE is a safe & MEDIAL RELEASE is a safe & easy technique with a good easy technique with a good sleevesleeve

LATERAL RELEASE is difficult LATERAL RELEASE is difficult and carry a high risk of and carry a high risk of secondary FT instability and secondary FT instability and may require more may require more constrained designs (or PCR)constrained designs (or PCR)

The effect of Extraarticular Varus The effect of Extraarticular Varus & Valgus Deformity& Valgus Deformity

on TKAon TKA

A.Wolff, D.Hungerford, C.Pepe

Clin.Orthop. 271: 35-51, 1991

MALUNIONSMALUNIONS

the closer to the the closer to the knee (like HTO)knee (like HTO)

the more is the the more is the consequent consequent malorientation of malorientation of the kneethe knee

25°25°

HKA: 176°HKA: 176° HKA: 159°HKA: 159°

If you want to create If you want to create coronal laxity in coronal laxity in extensionextension, you must e, you must elongate, releaselongate, release::

Iry & IIry & IIIry stabilizers in extensionry stabilizers in extensionMedially:Medially: MCLMCL ACL + PCLACL + PCL Posterior capsulePosterior capsule (severe destabilization)(severe destabilization)

INTRAARTICULAR CORRECTION INTRAARTICULAR CORRECTION of EA DEFORMITYof EA DEFORMITY

3rd MESSAGE

FEMUR FEMUR VARUMVARUM

consider:consider:

medial release, magnitudemedial release, magnitude distal resection of lateral distal resection of lateral

condyle condyle OK in extension but…. OK in extension but….

+

Rotate the femoral implant in Rotate the femoral implant in IRIRsubluxation of the Patellasubluxation of the Patella

but in flexion

in order to be stable:

+

IR

+

IRIR

if significantif significant femur varumfemur varum:: think of a tibial cut in slight valgusthink of a tibial cut in slight valgusa metaphyseal femoral osteotomya metaphyseal femoral osteotomyor a or a medial condylar osteotomy with medial condylar osteotomy with

flexion gap first and then bring the flexion gap first and then bring the osteotomized MC distallyosteotomized MC distally

Femur Femur VarumVarum

HKA 162°

TIBIA VALGUMTIBIA VALGUM consider :consider :

TibiaTibia (no consequence in F for (no consequence in F for the rotation of the femoral the rotation of the femoral implant)implant)

collateral lgts frame collateral lgts frame hinge perpendicularhinge perpendicular

Valgum= Valgum= lateral releaselateral release necessary to create necessary to create laxity in full extensionlaxity in full extension