Robotic Assistance in Simultaneous Bilateral Medial Unicompartmental Knee Arthroplasty: A Retrospective Cohort Study of 126 Knees Demonstrating Enhanced Radiographic Accuracy and Comparable Safety to Conventional Methods

Background: One-stage bilateral unicompartmental knee arthroplasty (BUKA) is a promising option for patients with bilateral medial knee osteoarthritis. This study aims to compare the safety, early clinical and functional outcomes, and radiological results of conventional vs robotic-assisted medial BUKA. Methods: A retrospective cohort study was conducted involving patients who underwent medial BUKA as a single-stage procedure between April 2016 and January 2022. The study included both conventional (36 procedures) and robotic-assisted techniques (90 procedures) with a minimum follow-up of 6 months. Conventional procedures were performed either simultaneously by two surgical teams or sequentially by one team. Robotic procedures were exclusively performed sequentially by a single team. Data on surgical outcomes, patient-reported outcome measures (International Knee Society score), and radiographic measurements were collected. Results: Among the 63 patients analyzed, robotic-assisted procedures took significantly longer (115 ± 22 minutes) compared to conventional approaches (86.9 ± 12 minutes; P < .0001). No significant differences were observed in complications, length of hospital stay, rehospitalizations, patient-reported outcome measures, or overall clinical outcomes. However, radiographic analysis showed superior joint line restoration in the robotic group (−0.2 ± 0.7 mm vs −1.4 ± 1.35 mm, P = .03) and better tibial implant varus control (0.3° ± 0.6 vs 1° ± 1.8 degrees, P = .03). Conclusions: While robotic-assisted BUKA resulted in longer operative times, clinical outcomes were comparable. Radiographic findings indicated improved implant positioning, suggesting potential benefits in implantation accuracy that warrant further research. Level of Evidence: IV.