You Tian, Yang Bei, Zhang Xin-Tao, Jiang Xiao-Cheng, Wang Shuang, Zhang Wen-Tao
Department of Sports Medicine and Rehabilitation, Peking University Shenzhen Hospital Nanshan Maternity & Child Healthcare Hospital of Shenzhen, Shenzhen, China.
Medicine (Baltimore). 2017 Mar;96(13):e6410. doi: 10.1097/MD.0000000000006410.
Gluteal muscle contracture (GMC) is a clinical syndrome characterized by gait abnormality and limb dysfunction, as well as secondary deformities of pelvis and femur. Femoroacetabular impingement (FAI) typically could be diagnosed on the basis of computed tomography (CT) such as the equatorial-edge angle (EE angle), but it did not work well in GMC patients. In this study, we retrospected all image data and found small EE angles in GMCs, which meant retroverted acetabulum; however, none of them showed no symptoms and signs of FAI. Therefore, we had reasons to think that, some normal hips with unbalanced hip myodynamia as same as GMCs, may be incorrectly diagnosed as FAI through measuring EE angle only.In consequence, the paper was designed to assess the use of the EE angle in the assessment of FAI in the diagnosis, as described by Werner.Twenty-three patients (46 hips) were collected and calculated with the "equatorial-edge angle" (EE angle) by CT scans. All of them were excluded from FAI.Review of the hips showed a mean EE angle was 12.93°, with a minimum of -3.42° and a maximum of 24.08°. The mean value for males and females were 13.52° and 12.40°, respectively, without statistical significance, although the mean value of left hips and right sides reached 13.32° and 12.54° individually, not having statistical differences neither. There were not any symptoms or signs of FAI in all patients. Thus, the reduced EE angle could suggest the local excessive coverage of the femoral head by the anterior acetabular edge, but might not be a reasonably good predictor of FAI.GMC patient's acetabular deformity mainly manifests as increased retroversion, which may be the anatomical basis for FAI and lead to high risks of the acetabular impingement. However, all patients in this study showed no symptoms and signs of FAI, suggesting that the measurement of EE angle can only be applied to assessing those people with normal hip myodynamia, and the bone deformity and the muscular disorder should be both considered in the diagnosis of FAI.
臀肌挛缩症（GMC）是一种以步态异常、肢体功能障碍以及骨盆和股骨继发性畸形为特征的临床综合征。股骨髋臼撞击症（FAI）通常可根据计算机断层扫描（CT），如赤道边缘角（EE角）进行诊断，但在GMC患者中效果不佳。在本研究中，我们回顾了所有影像数据，发现GMC患者的EE角较小，这意味着髋臼后倾；然而，他们均未表现出FAI的症状和体征。因此，我们有理由认为，一些与GMC患者一样存在髋关节肌力不平衡的正常髋关节，仅通过测量EE角可能会被误诊为FAI。因此，本文旨在评估如Werner所述的EE角在FAI诊断评估中的应用。收集了23例患者（46髋），通过CT扫描计算“赤道边缘角”（EE角）。所有患者均排除FAI。对这些髋关节的检查显示，平均EE角为12.93°，最小值为-3.42°，最大值为24.08°。男性和女性的平均值分别为13.52°和12.40°，无统计学意义，尽管左侧髋关节和右侧的平均值分别达到13.32°和12.54°，也无统计学差异。所有患者均无FAI的任何症状或体征。因此，EE角减小可能提示髋臼前缘对股骨头的局部覆盖过多，但可能不是FAI的合理良好预测指标。GMC患者的髋臼畸形主要表现为后倾增加，这可能是FAI的解剖学基础，并导致髋臼撞击的高风险。然而，本研究中的所有患者均未表现出FAI的症状和体征，这表明EE角测量仅适用于评估髋关节肌力正常的人群，在FAI的诊断中应同时考虑骨骼畸形和肌肉紊乱。
