Rehabilitation Unit, Kyoto University Hospital, 54 Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto, 606-8507, Japan.
Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Skeletal Radiol. 2024 May;53(5):967-974. doi: 10.1007/s00256-023-04516-z. Epub 2023 Nov 24.
This study aimed to investigate the association between muscle density as an indicator of fatty infiltration of lower extremity muscles and physical activity (PA) after total hip arthroplasty (THA) and identify the patient characteristics with high postoperative PA.
This study included 62 female patients who underwent THA for unilateral hip osteoarthritis. Muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles was measured using computed tomography (CT). PA was assessed using University of California, Los Angeles (UCLA) activity scores. CT and UCLA activity score were obtained before and 1 year after THA. The patients were divided into two groups, sufficient (score ≥ 6) and insufficient (score < 6) activity groups, based on their level of PA as determined by their UCLA activity score 1 year after THA. The association of PA with the amount of changes in muscle density was examined with Spearman's rank correlation coefficient. Logistic regression analysis was performed to identify postoperative factors determining PA at 1 year after THA.
Spearman's rank correlation coefficient showed a significantly positive association between recovery in PA and an increase in muscle density of the gluteus maximus, gluteus medius, iliopsoas, and quadriceps muscles. Additionally, logistic regression analysis confirmed that postoperative muscle densities of the gluteus maximus and quadriceps muscles were variables determining the PA 1 year after THA.
The findings of this study indicated that the improvement of fatty infiltration in lower limb muscles, especially in the gluteus maximus and quadriceps, is likely to promote the increase in postoperative PA.
本研究旨在探讨下肢肌肉密度（脂肪浸润的指标）与全髋关节置换术后体力活动（PA）之间的关系，并确定术后 PA 较高的患者特征。
本研究纳入了 62 名因单侧髋骨关节炎接受全髋关节置换术的女性患者。使用计算机断层扫描（CT）测量臀大肌、臀中肌、髂腰肌和股四头肌的肌肉密度。使用加利福尼亚大学洛杉矶分校（UCLA）活动评分评估 PA。在 THA 前和 THA 后 1 年分别获取 CT 和 UCLA 活动评分。根据患者在 THA 后 1 年的 UCLA 活动评分，将其分为足够（评分≥6）和不足（评分<6）活动组。采用 Spearman 秩相关系数检验 PA 与肌肉密度变化量之间的相关性。采用 logistic 回归分析确定术后 1 年决定 PA 的因素。
Spearman 秩相关系数显示，PA 的恢复与臀大肌、臀中肌、髂腰肌和股四头肌肌肉密度的增加呈显著正相关。此外，logistic 回归分析证实，术后臀大肌和股四头肌肌肉密度是决定 THA 后 1 年 PA 的变量。
本研究结果表明，下肢肌肉脂肪浸润的改善，特别是臀大肌和股四头肌的改善，可能会促进术后 PA 的增加。
