A Comparison of Coronal Plane Axial Femoral Relationships in Asian Patients With Varus Osteoarthritic Knees and Healthy Knees

Standing full-length radiographs were measured to compare coronal femoral axes between 250 limbs in patients with varus osteoarthritis with 50 healthy controls. Mean distal femoral axis-mechanical axis angle was 7.3° ± 1.6°, and mean femoral bow was 3.6° ± 2.5° in patients compared to 5.5° ± 0.8° and 0.4° ± 1.2°, respectively, in controls. Femoral condylar-mechanical axis angle was significantly lower in osteoarthritic limbs (89.9° + 2.8°) as compared to controls (93.1° + 1.6°). Varus deformity correlated significantly with femoral bowing (P < .05; correlation coefficient, 0.4). Osteoarthritic limbs (18.8%) showed a distal femoral axis-mechanical axis angle more than 9°. These findings have implications in deciding the optimum valgus angle at which to perform distal femoral resection in total knee arthroplasty.