OBJECTIVE To analyze regional muscle CT density and bulk in femoroacetabular impingement (FAI) and hip dysplasia (HD) versus controls. MATERIALS AND METHODS Patients who obtained perioperative CT imaging for FAI and HD before surgery were retrospectively studied. Asymptomatic controls included for comparison. Two readers independently evaluated regional hip muscle [iliopsoas (IP), rectus femoris (RF), gluteus minimus (Gm), and medius (GM)] density, muscle area, and muscle circumference. Inter-observer reliability calculated using intra-class correlation coefficient (ICC). RESULTS A consecutive series of 25 FAI patients, 16 HD patients, and 38 controls were recruited in the study. FAI patients had significantly greater Gm and GM circumferences as well as greater RF and IP areas on the normal side compared to the asymptomatic control group (p values 0.004, 0.032, 0.033, and 0.028, respectively). In addition, Gm and RF circumferences and RF area were significantly larger (p values 0.029, 0.036, and 0.014, respectively) in FAI patients on the affected side compared to the control group. HD patients had significantly smaller Gm and GM circumferences on the affected side than normal side measurements in FAI group (p values 0.043 and 0.003, respectively). Normal side GM circumference was also smaller in HD patients than normal side FAI hips (p value 0.02). There was no significant difference between the measurements on normal and abnormal sides in each disease group. No significant difference was found between measurements of HD compared to controls (p > 0.05). No muscle density differences were seen among different groups. There was moderate to excellent inter-reader reliability for all measurements except Gm muscle density. CONCLUSIONS Muscle analysis was able to quantify differences among patients with FAI, HD, and asymptomatic controls. These changes could indicate either a muscle imbalance contributing to the pathology or disuse atrophy, which may have implications for specific muscle-strengthening therapies and rehabilitation procedures in such patients.

中文翻译：

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成人股骨髋臼撞击和髋关节发育不良的髋关节功能障碍的局部肌肉变化。

目的分析股骨髋臼撞击（FAI）和髋关节发育不良（HD）与对照组的区域肌肉CT密度和体积。材料与方法回顾性分析术前获得FAI和HD的围手术期CT影像的患者。包括无症状对照用于比较。两名读者分别评估了区域性臀部肌肉[[肌（IP），股直肌（RF），臀小肌（Gm）和臀肌（GM）]的密度，肌肉面积和肌肉周长。使用组内相关系数（ICC）计算的观察者间可靠性。结果该研究连续招募了25例FAI患者，16例HD患者和38例对照。与无症状对照组相比，FAI患者的正常人的Gm和GM周长明显更大，RF和IP面积也更大（分别为p值0.004、0.032、0.033和0.028）。此外，与对照组相比，患侧FAI患者的Gm和RF周长以及RF面积明显更大（分别为p值0.029、0.036和0.014）。在FAI组中，HD患者患侧的Gm和GM周长明显小于正常侧的测量值（分别为p值0.043和0.003）。HD患者的正常侧GM周长也小于正常侧FAI髋关节（p值0.02）。在每个疾病组的正常和异常侧的测量值之间没有显着差异。与对照相比，HD测量之间没有发现显着差异（p> 0.05）。不同组之间未见肌肉密度差异。除Gm肌肉密度外，所有测量的阅读器间可靠性中等到极好。结论肌肉分析能够量化FAI，HD和无症状对照患者之间的差异。这些变化可能表明肌肉病理失衡或病理性萎缩或废用性萎缩，这可能会影响此类患者的特定肌肉强化疗法和康复程序。结论肌肉分析能够量化FAI，HD和无症状对照患者之间的差异。这些变化可能表明肌肉病理失衡或病理性萎缩或废用性萎缩，这可能会影响此类患者的特定肌肉强化疗法和康复程序。结论肌肉分析能够量化FAI，HD和无症状对照患者之间的差异。这些变化可能表明肌肉病理失衡或病理性萎缩或废用性萎缩，这可能会影响此类患者的特定肌肉强化疗法和康复程序。