POSTEROMEDIAL VERTICAL CAPSULOTOMY INCREASES THE MEDIAL EXTENSION GAP IN TOTAL KNEE ARTHROPLASTY

IntroductionA small medial extension gap (EG) needs posterior soft tissue release to avoid undesirable additional resection of the distal femur in total knee arthroplasty (TKA). However, the effect of this procedure on the EG is not always sufficient because the EG is influenced not only by the posterior soft tissue but also by the medial collateral ligament (MCL). We hypothesize that contracture of the posterior capsule prevents full elongation of the MCL in extension and we investigated the efficacy of posteromedial vertical capsulotomy (PMVC) on the medial EG which separate MCL from the posterior capsule (Fig. 1).Materials and MethodsThe PMVC was performed on 128 knees in which the medial extension gap was considered too small. The EG was initially created with a standard femoral distal cut and tibial cut. To estimate the gaps more precisely before flexion gap (FG) adjustment at the final step of the surgery, we performed a 4 mm precut of the posterior femoral condyle and measured the gaps with the pat...