Influence of femoral anatomy on valgus correction angle in total knee arthroplasty among Indian patients.

Abstract

This study evaluated the relationship between the valgus correction angle (VCA) and femoral parameters-neck-shaft angle (NSA), horizontal offset (HO), femoral length (FL), lateral distal femoral angle (LDFA), and hip-knee-ankle angle (HKA)-in Indian patients undergoing total knee arthroplasty (TKA). This study aims to assess the importance of individualized VCA adjustments, as opposed to fixed values, in optimizing surgical planning for the Indian population. A retrospective analysis was conducted on 400 patients (319 females, 81 males; mean age 65.14 years) undergoing TKA. Standardized preoperative scanograms were analyzed and parameters measured. Multiple linear regression was used to assess the relationship between VCA and femoral parameters. The mean VCA was 6.5° ± 1.66°. LDFA had the strongest positive association with VCA (p < 0.001), followed by a significant negative correlation with HKA (p = 0.001) and FL (p = 0.004). NSA and HO showed no significant effect. The model was significant (F = 26.54, p < 0.05), explained 32.1% of the variance in VCA (adjusted R² = 0.321), with LDFA emerging as the most influential predictor. The Durbin-Watson statistic (2.028) indicated no autocorrelation, suggesting independent influence of the parameters. LDFA, HKA, and FL significantly influence VCA in Indian patients, underscoring the need for individualized preoperative VCA planning to enhance surgical accuracy in TKA. Taller patients and valgus knees require a lesser VCA than shorter patients with varus. The wide variation in VCA values supports the need for individualized preoperative planning rather than a one-size-fits-all approach.