Effect of individualized distal femoral valgus resection angle in primary total knee arthroplasty: A systematic review and meta-analysis involving 1300 subjects

Abstract

Background: Proper limb alignment and implant positioning are important for successful total knee arthroplasty (TKA). Whether any differences exist in restoration of limb alignment for valgus knees between fixed and individual femoral valgus correction angle (VCA) for distal femoral resection remains unknown.

Methods: The PubMed, Medline, Embase, and Wangfang databases were searched to identify studies comparing individualized VCA and fixed VCA in the distal femoral valgus resection. The primary outcomes were the mechanical femorotibial angle (MFT angle) and the proportion of postoperative alignment deviation within ±3°. The secondary outcomes were femoral valgus correction angle (VCA), component angle (α angle and β angle).

Results: Six studies with 1167 TKAs were analyzed quantitatively. The coronal limb alignments in individualized group were closer to neutral than fixed group with a mean 0.77° difference (95% CI, -1.43 to -0.11; P = .022; I² = 71.0%). Moreover, there were more patients' postoperative alignment deviation within neutral ±3° in the individualized group (RR, 1.23; 95% CI, 1.09 to 1.38; P = .00; I² = 36.4%). The α angle were closer to neutral in the individualized group, and there's 1.2° more deviation from neutral in the fixed group (95% CI, 0.99 to 1.41; P = .00; I² = 0%). No difference was found in the β angle between groups (WMD, 0.85; 95% CI, -0.09 to 1.78; P = .075; I² = 88.3%).

Conclusions: This systematic review and meta-analysis demonstrated that the individualized VCA for distal femoral resection could enhance the accuracy of postoperative limb alignment and femoral component alignment in the coronal plane. However, further high-quality RCTs and well-designed trials are still needed.

Keywords: Distal femoral resection; Meta-analysis; Total knee arthoplasty; Valgus correction angle.