Factors Influencing the Valgus Cut Angle-during Total Knee Arthroplasty-in Indian Population

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

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Outcomes of cruciate-retaining total knee arthroplasty for osteoarthritis with severe varus deformity

BACKGROUND

Varus deformity is common in osteoarthritic knee. The purpose of this study was to investigate the clinical and radiographic outcomes after cruciate-retaining (CR) total knee arthroplasty (TKA) for severely varus osteoarthritic knees and compare them to those of mildly to moderately deformed osteoarthritic knees.

METHODS

Eight hundred ninety-four subjects were undergone CR TKA, 137 had severe varus deformity (group 1), and 757 had mild-to-moderate deformity (group 2) of the lower limb preoperatively. Pre- and postoperative outcomes were compared between two groups clinically and radiographically.

RESULTS

Mean follow-up period was 54.7 ± 28.9 months. Mean age was 77.8 ± 6.7 years in group 1 and 74.5 ± 7.4 years in group 2 (p < 0.001). Preoperative hip-knee-ankle angle (HKAA) was - 17.7°±2.9° in group 1 and - 6.3° ± 5.1° in group 2 (p < 0.001). Preoperative range of motion (ROM) was 127.7° ± 15.2° in group 1 and 130.8 °± 9.6° in group 2 (p = 0.019). Preoperative Knee Society scores and WOMAC score were not significantly different between two groups. Postoperative HKAA was - 0.4° ± 2.3° in group 1 and 0.6 ° ± 2.0° in group 2 (p < 0.001). Postoperative ROM, Knee Society scores, and WOMAC score were not significantly different between two groups.

CONCLUSIONS

CR TKA showed results in subjects with severe varus deformities comparable to those without severe varus deformities. Whether the degree of preoperative varus deformity of the lower limb should be considered when deciding to perform CR-type or PS-type TKA requires further discussion.

LEVEL OF EVIDENCE

Retrospective comparative study, Level III.