High return to sport rate in patients undergoing image-based robotic arm assisted unicompartmental knee arthroplasty

Introduction: This study was aimed to assess the return to sport (RTS) rate in patients who underwent CT-based robotic-assisted unicompartmental knee arthroplasty (RA-UKA) and to evaluate the clinical performance and the assocition between patients’ sport activity levels and Patient Reported Outcome Measures after surgery. Materials and methods: This retrospective study included 218 patients undergoing medial RA-UKA with fixed-bearing implants, performed at a single center between 2014 and 2019. Patients were allocated into two groups based on sport’s practice and were administered the University of California, Los Angeles (UCLA) activity scale, Forgotten Joint Score-12 (FJS-12), Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) and the 5-Level Likert Scale. Results: A total of 136 patients were included for assessment. The overall RTS rate after surgery was 93.1%. Six subjects who did not practice sport preoperatively, were able to start sport activities after surgery and all patients performing sports preoperatively, returned to same activity level. The mean UCLA and FJS-12 scores in the group of patients practicing sports were significantly higher than in the no-sport group (p < 0.001 and p < 0.05, respectively). Patients who practiced sports were more likely to attain higher FJS-12 and UCLA scores than those who were not performing physical activity. Conclusions: Patients undergoing RA-UKA showed a 93.1% RTS rate after surgery. Differences were detected in terms of postoperative UCLA and FJS-12 scores between patients who performed and who did not practice sport activities after surgery. High levels of postoperative UCLA scores were associated with higher KOOS-JR and patients’ satisfaction.