Computer-assisted osteotomy of the lateral femoral condyle with non-constrained total knee replacement in severe valgus knees.

We describe the mid-term results of a prospective study of total knee replacement in severe valgus knees using an osteotomy of the lateral femoral condyle and computer navigation. There were 15 knees with a mean valgus deformity of 21 degrees (17 degrees to 27 degrees) and a mean follow-up of 28 months (24 to 60). A cemented, non-constrained fixed bearing, posterior-cruciate-retaining knee prosthesis of the same design was used in all cases (Columbus-B. Braun; Aesculap, Tuttlingen, Germany). All the knees were corrected to a mean of 0.5 degrees of valgus (0 degrees to 2 degrees). Flexion of the knee had been limited to a mean of 85 degrees (75 degrees to 110 degrees) pre-operatively and improved to a mean of 105 degrees (90 degrees to 130 degrees) after operation. The mean Knee Society score improved from 37 (30 to 44) to 90 points (86 to 94). Osteotomy of the lateral femoral condyle combined with computer-assisted surgery gave an excellent mid-term outcome in patients undergoing total knee replacement in the presence of severe valgus deformity.