Geriatrics & Gerontology International · Nov 5, 2025
Association Between Fatty Infiltration of the Gluteus Medius Muscle and Falls After Total Hip Arthroplasty in Female Patients With Unilateral Primary Hip Osteoarthritis: A Retrospective Cohort Study
By Shinonaga A, Matsumoto H, Uekawa M et al.
AIM: The fatty infiltration of the gluteus medius may be associated with falls after total hip arthroplasty (THA); however, the supporting evidence is lacking. This study aimed to determine which of the following indices are most related to falls after THA in female patients with unilateral primary hip osteoarthritis (OA): preoperative fatty infiltration of the gluteus medius, hip abductor muscle strength, and gluteus medius muscle mass. METHODS: This was a single-institution retrospective cohort study involving female patients who had undergone primary THA. The outcome of this study was the incidence of falls in the first year after THA. Fatty infiltration and gluteus medius muscle mass were assessed using preoperative computed tomography (CT). Fatty infiltration was estimated using muscle density. Associations between fatty infiltration of the gluteus medius, hip abductor muscle strength, and gluteus medius muscle mass, and falls were analyzed using multivariate logistic regression analysis (covariates: age, number of medications, pain during walking, and history of falls). RESULTS: A total of 116 participants were included in the analysis. Thirty participants (25.9%) fell within the first year of THA. Only the fatty infiltration of the gluteus medius (odds ratio, 0.93; 95% confidence interval, 0.88-0.99; p = 0.029) was a significant predictor of falls after THA. CONCLUSIONS: Our findings indicate a potential association between fatty infiltration of the gluteus medius muscle and falls in female patients who underwent THA.