RESULTS FOLLOWING A MEDIAL APPROACH TO A VALGUS KNEE IN TOTAL KNEE ARTHROPLASTY.

Abstract

Purpose: We describe our management of the valgus knee including release of tight lateral structures using a medial approach.

Method: Controversy surrounds which approach to use when undertaking a total knee replacement (TKR) in a fixed valgus knee. Poor patellar tracking is associated with this deformity and often rectified by a lateral retinacular release. Those favoring the lateral approach feel, although more demanding, it gives direct access to the tight lateral structures and avoids excessive devas-cularization to the patella, which may be associated with a lateral release and a medial arthrotomy.

Two hundred and eight consented patients (24.2%) were identified from 860 primary knee arthroplasties carried out over a 33-month period by a single surgeon. An LCS mobile bearing prosthesis was used in all cases. The mean valgus deformity measured 12.1 degrees (range 1–38). Fifty four percent of patients had a deformity of greater than 10 degrees. The patella was not resurfaced in any patient.

Results: Forty-four patients (21%) required no soft tissue release. The mean deformity was 6 degrees (range 2–13). Of the remaining 164 patients, 142 (87%) had a posterolateral capsule release, 17 (10%) posterolateral capsule and iliotibial band release, 4 (2.4%) posterolateral and direct posterior capsule release and 1 (0.6%) a lateral collateral ligament slide for fixed valgus deformity. The mean valgus deformity increased with each additional release required.

Of note 61 (29.3%) patients required a lateral patellar release for patellar maltracking. No patellar complications were noted. Mean patellar tilt was 1.1 degrees (sd=0.6 degrees) and mean patellar congruency 98% (sd=0.7%).

Conclusion: Using a medial approach in the valgus knee is technically less demanding than a lateral approach, can be used in any primary knee irrespective of the type of deformity and can restore patellar alignment without compromising viability at least in cases where the patella is not resurfaced.