Comparison of post-operative kneeling ability in patients with varus knee osteoarthritis: unicompartmental knee arthroplasty versus open-wedge high tibial osteotomy

This study compared post-operative kneeling abilities following unicompartmental knee arthroplasty (UKA) and open-wedge high tibial osteotomy (OWHTO) for varus knee osteoarthritis. This retrospective cohort study included 127 knees that underwent UKA and 100 knees that underwent OWHTO between 2018 and 2022. Clinical data, including Knee injury and Osteoarthritis Outcome Score (KOOS) and the University of California, Los Angeles (UCLA) activity score, were collected pre-operatively and at a minimum 12 month follow-up. Kneeling ability was defined using the KOOS Sp5 subscore. Factors influencing post-operative kneeling, including age, pre- and post-operative knee flexion angle, pre-operative UCLA activity score, degree of osteoarthritis, femorotibial angle, pre-operative kneeling ability, and surgical procedure, were evaluated using multiple linear regression analysis. OWHTO demonstrated significantly better post-operative kneeling ability than UKA. Pre-operative kneeling ability and surgical procedure statistically significantly influenced post-operative outcomes (regression coefficient −0.50, 95% confidence interval −0.003–0.99; p ​= ​0.049). OWHTO was significantly associated with better Sp5 scores and improved post-operative kneeling ability, emphasizing the importance of choosing the appropriate surgical technique for better post-operative kneeling ability. • Comparison between unicompartmental knee arthroplasty (UKA) and open-wedge high tibial osteotomy (OWHTO). • OWHTO demonstrated better post-operative kneeling ability than UKA. • The surgical procedure used can influence post-operative kneeling ability. • Appropriate decision-making is required to ensure better post-operative outcomes.