Comparison of Postoperative Complications following High Tibial Osteotomy and Unicompartmental Knee Arthroplasty in Patients with Obesity.

Abstract

Background Both high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) maintain distinct roles in the operative management of unicompartmental knee osteoarthritis. Whilst both procedures have traditionally been approached with caution in patients with obesity, the rising prevalence of obesity has led to increasing numbers of these patients undergoing surgical management. Despite this, limited evidence directly compares short-term complication profiles between HTO and UKA in obese populations. This study aims to evaluate 30-day outcomes in patients with obesity undergoing HTO versus UKA. Methods A national surgical repository was queried for patients with obesity undergoing HTOs and UKAs from 2008 to 2020. Patient demographics, medical comorbidities, and thirty-day outcomes were compared. Data were analyzed using Chi-Squared tests and binary logistic regression. 3,424 UKAs and 86 HTOs were included. The HTO cohort had a greater proportion of male (67.4% vs 44.2%, p<0.001) and Black (10.5% vs. 6.9%, p<0.001) patients compared to the UKA cohort. The UKA cohort had a greater proportion of patients with diabetes mellitus (14.0% vs 4.7%, p=0.010), hypertension (50.3% vs 29.1%, p<0.001), and American Society of Anesthesiologists (ASA) Class of 3 or 4 (39.5% vs 19.8%, p<0.001). Results Postoperative complications were higher in HTO patients. Wound infections (5.8% vs. 1.1%, p=0.003) and cumulative complication rates (7.0% vs. 2.0%, p=0.010) were higher in HTO compared to UKA. HTO was similarly associated with higher odds of wound infections (OR 6.6; 95% CI 2.5-18.0; p<0.001) and any-cause complication (OR 4.8; 95% CI 2.0-11.7; p=0.001). Conclusion While complication rates are overall low after HTO and UKA, obese patients undergoing HTO maintain higher odds of 30-day complications relative to their UKA counterparts. Assuming both procedures could be indicated for the patient's deformity and pattern of arthritis, obese patients may be better suited for UKA to minimize complications.