Conventional versus robotic total knee arthroplasty – a comparative study of accuracy, alignment and early functional results

Background: Restoration of mechanical alignment and optimization of functional outcomes are critical for total knee arthroplasty (TKA). Robotic systems aim to improve the accuracy of bone cuts and reduce malalignment. Evidence from Indian populations remains limited. Methods: The present study was a prospective, non-randomized control study. The sample size was 43 knees in each group (robotic and traditional), for a total of 86 knees, using a two-sided α=0.05 and power of 80%. Functional outcomes were evaluated with oxford knee score (OKS) and knee society score (KSS) at 0 weeks, 6 weeks, 3 months and 6 months. Perioperative variables, including operative time, blood loss, length of stay, pain score and complications, were recorded. Results: Baseline demographic and clinical characteristics were comparable between groups. Robotic TKA demonstrated fewer alignment outliers (11.6% versus 25.6%, p=0.166) and significantly lower mean absolute HKA error (1.4°±1.1 versus 2.4°±1.7, p=0.002). Functional outcomes improved in both groups over time. Robotic TKA showed higher OKS at 6 weeks (32.2±3.5 versus 29.9±4.3, p=0.009) and higher KSS at 6 weeks (75.6±9.7 versus 69.6±7.9, p=0.003) and 6 months (90.3±4.9 versus 85.0±5.6, p<0.001). Robotic TKA required longer operative time (94.2±9.4 versus 81.9±9.7 min, p<0.001) but resulted in lower blood loss (293.9±52.2 versus 350.5±46.3 ml, p<0.001). Length of stay and complication rates were similar between groups. Conclusions: Robotic TKA improves alignment accuracy and enhances early functional outcomes compared to conventional techniques, with acceptable perioperative safety in Indian settings.