Human Health Sciences, Graduate School of Medicine, Kyoto University, 53-Kawahara-Cho, Shogoin, Sakyo-Ku, Kyoto, 606-8507, Japan.
Faculty of Rehabilitation, Kansai Medical University, Hirakata, Japan.
Arthritis Res Ther. 2023 Apr 14;25(1):61. doi: 10.1186/s13075-023-03048-0.
The characteristics of muscle degeneration in individual quadriceps in early knee osteoarthritis (OA) and the association of muscle quantity and quality on knee dysfunction remain unclear. This study aimed to clarify the characteristics of muscle degeneration in individual quadriceps muscles in early knee OA and elucidate the association of muscle volume and intramuscular adipose tissue (intraMAT) with knee dysfunction, including functional disabilities, symptoms, and joint morphology.
Fifty participants were categorized into early knee OA and healthy control groups. 3.0 T magnetic resonance imaging (MRI) using T1-weighted and Dixon methods and 3D SPACE in the thigh muscle and knee joint regions was performed. Quadriceps muscle volume, intraMAT, and whole-organ MRI score (WORMS) were assessed. The Knee Society Score (KSS) was used to evaluate functional disabilities and knee symptoms. Univariate analysis of variance was conducted with covariates to clarify the differences in muscle volume and intraMAT between the two groups. Multiple linear regression analyses were performed using the KSS function and symptom subcategories and WORMS as dependent variables and muscle volume, intraMAT, and the presence of early knee OA as independent variables, such as potential confounders.
The quadriceps intraMAT, especially in the vastus medialis (VM), was significantly higher in patients with early knee OA than in healthy controls. The VM intraMAT, not muscle volume, was significantly associated with KSS function [B = - 3.47; 95% confidence interval [CI], - 5.24 to - 1.71; p < 0.001] and symptom scores [B = - 0.63; 95% CI, - 1.09 to - 0.17; p = 0.008], but not with WORMS.
These findings suggest that higher VM intraMAT is characteristic of quadriceps muscle degeneration in early knee OA and its increase is associated with functional disabilities and symptoms.
在早期膝关节骨关节炎（OA）中，个体股四头肌的肌肉退化特征以及肌肉量和质量与膝关节功能障碍的关系尚不清楚。本研究旨在阐明早期膝关节 OA 中个体股四头肌肌肉的退化特征，并阐明肌肉体积和肌内脂肪组织（intraMAT）与膝关节功能障碍（包括功能障碍、症状和关节形态）的关系。
将 50 名参与者分为早期膝关节 OA 组和健康对照组。使用 3.0T 磁共振成像（MRI），采用 T1 加权和 Dixon 方法以及大腿肌肉和膝关节区域的 3D SPACE，评估股四头肌体积、intraMAT 和全器官 MRI 评分（WORMS）。使用膝关节协会评分（KSS）评估功能障碍和膝关节症状。使用协方差进行单变量方差分析，以明确两组间肌肉体积和 intraMAT 的差异。使用 KSS 功能和症状亚分类以及 WORMS 作为因变量，肌肉体积、intraMAT 和早期膝关节 OA 的存在作为自变量，进行多元线性回归分析，如潜在混杂因素。
与健康对照组相比，早期膝关节 OA 患者的股四头肌 intraMAT，特别是股直肌（VM），明显更高。VM intraMAT，而不是肌肉体积，与 KSS 功能显著相关[B= -3.47；95%置信区间（CI），-5.24 至-1.71；p<0.001]和症状评分[B= -0.63；95% CI，-1.09 至-0.17；p=0.008]，但与 WORMS 无关。
这些发现表明，VM 内的较高 intraMAT 是早期膝关节 OA 中股四头肌肌肉退化的特征，其增加与功能障碍和症状有关。
