Sex Differences in Sarcopenia in Patients Undergoing Total Knee Arthroplasty for Advanced Knee Osteoarthritis.

Background and Objectives: The purpose of this study was to compare sex differences in the incidence of sarcopenia, demographic characteristics, and preoperative sarcopenic parameters in patients undergoing TKA for advanced knee osteoarthritis (OA). Moreover, we sought to compare patient-reported outcome measures (PROMs) and the predisposing factors after TKA in patients with sarcopenia by sex through subgroup analysis. Materials and Methods: From May 2020 to September 2022, a total of 892 patients who were evaluable for sarcopenia before primary TKA were enrolled. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Patients were assessed according to the presence or absence of sarcopenia. After a two-to-one matched-pair analysis for subgroup analysis, 21 knees in men were matched with a corresponding number of knees in women (42), resulting in a total of 63 knees. PROMs were investigated using the Knee Injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Osteoarthritis Index, and the Short Form-12 physical and mental component summary scores. Moreover, the postoperative complications and predisposing factors for male sarcopenia were investigated. Results: The prevalence of sarcopenia was 10.9% (97/892), and the prevalence was higher in men (19.6%, 21/107) than in women (9.7%, 76/785). In subgroup analyses, male patients had significantly inferior PROMs up to 12 months after index surgery. Moreover, there was no significant difference in the systemic complications between the two groups. Multivariate binary logistic regression analysis indicated that alcohol consumption, smoking, and higher modified Charlson Comorbidity Index (mCCI) were predisposing factors for male patients with sarcopenia. The prevalence of sarcopenia was higher in male patients undergoing primary TKA. Conclusions: When compared with the propensity-matched female group, male patients had inferior PROMs up to 12 months postoperatively. Alcohol consumption, current smoker status, and higher mCCI were predisposing factors for sarcopenia in male patients with advanced knee OA.