Robotic-assisted total knee arthroplasty leads to early functional improvement in patient-reported outcome among obese patients: A retrospective cross-sectional study

Robotic-assisted total knee arthroplasty (RaTKA) improves radiological alignment compared to conventional TKA, but its impact on functional outcomes in obese patients remains unclear. This study evaluates whether RaTKA enhances postoperative functional recovery in obese patients. A retrospective review (January 2009 to May 2024) included consecutive obese patients who underwent unilateral primary TKA by a single senior surgeon using either RaTKA or conventional methods. The body mass index was recorded during the final preoperative clinic visit. Functional outcomes were assessed using the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) at three months and one year. Statistical analysis was performed using SPSS version 29. The study included 200 patients in the three-month cohort and 206 patients in the one-year cohort. RaTKA patients were younger and had a lower Charnley Class C rate. At three months, the RaTKA group demonstrated superior functional outcomes, including higher KOOS ADL (82.84 vs. 75.35, p = 0.003), KOOS Sport (58.90 vs. 50.42, p = 0.050), KOOS JR (73.15 vs. 67.54, p = 0.010), WOMAC function (11.73 vs. 16.83, p = 0.002), and WOMAC total (17.93 vs. 24.04, p = 0.009). By one year, outcomes were comparable between groups. RaTKA improves early functional recovery in obese patients but does not confer long-term advantages over conventional TKA. Future studies should explore the long-term clinical and cost-effectiveness of RaTKA in obese patients.