Comparison of postoperative kneeling ability in patients with varus knee osteoarthritis: Unicompartmental knee arthroplasty vs. open-wedge high tibial osteotomy

This study compared postoperative kneeling abilities following unicompartmental knee arthroplasty and open-wedge high tibial osteotomy for varus knee osteoarthritis. This retrospective cohort study included 127 and 100 knees that underwent unicompartmental knee arthroplasty and open-wedge high tibial osteotomy, respectively, between 2018 and 2022. Clinical data, including Knee Injury and Osteoarthritis Outcome Score and the University of California, Los Angeles activity score, were collected preoperatively and at a minimum 12-month follow-up. For bilateral knee procedures, data for each knee were recorded separately. Kneeling ability was defined using the Knee Injury and Osteoarthritis Outcome Sp5 sub-score. Factors influencing postoperative kneeling, including age, preoperative knee flexion angle, preoperative University of California, Los Angeles activity score, degree of osteoarthritis, femorotibial angle, preoperative kneeling ability, and surgical procedure, were evaluated using multiple linear regression analyses. Open-wedge high tibial osteotomy demonstrated significantly better postoperative kneeling ability than unicompartmental knee arthroplasty. Preoperative kneeling ability and surgical procedure significantly influenced postoperative outcomes (regression coefficient; 0.51, 95% confidence intervals; 0.02-1.00, p = 0.04). Open-wedge high tibial osteotomy was significantly associated with better Sp5 scores and improved postoperative kneeling ability, emphasizing the importance of surgical techniques for better postoperative kneeling ability.