Departments of Clinical Anatomy (M.T. and K.A.) and Functional Joint Anatomy (A.N.), Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
J Bone Joint Surg Am. 2019 Jan 16;101(2):177-184. doi: 10.2106/JBJS.18.00602.
Gluteus medius tears are a common hip disorder. Despite this, the etiology of these tears and the anatomical background of the gluteus medius tendon remain unclear. This study aimed to clarify the characteristics of the gluteus medius tendon. We hypothesized that the tendinous portions of the gluteus medius have a nonuniform structure contributing to the tear etiology.
Twenty-five hips from 15 Japanese cadavers were analyzed. Twenty-one of the hips were analyzed macroscopically, and the other 4 were analyzed histologically. In all of the specimens, the 3-dimensional (3D) morphology of the greater trochanter was examined using microcomputed tomography (micro-CT). In 10 of the 21 hips analyzed macroscopically, the local thickness of the gluteus medius tendon, detached from the greater trochanter, was measured.
The posterior and anterolateral parts of the gluteus medius tendons were roughly distinguished on the basis of the aspects of the iliac origins. The posterior part of the gluteus medius tendon ran in a fan-like shape and converged onto the superoposterior facet of the greater trochanter. The anterolateral part ran posteroinferiorly toward the lateral facet of the greater trochanter. The thickness was greater in the posterior part than in the anterolateral part, and the border between these 2 parts was relatively thin compared with the other parts. The histological study showed that both the posterior and anterolateral parts inserted onto the greater trochanter via fibrocartilage.
The gluteus medius tendon consists of thick posterior and thin anterolateral parts, which were identified by the facet or aspect of the bone structures and thinness of their border region.
Our findings indicate that, given the nonuniform structure of the gluteus medius tendon, the thin anterolateral part may be more prone to tears than the thick posterior part is and tears may generally be limited to the anterolateral part.
臀中肌撕裂是一种常见的髋关节疾病。尽管如此，这些撕裂的病因以及臀中肌肌腱的解剖背景仍不清楚。本研究旨在阐明臀中肌肌腱的特征。我们假设臀中肌的肌腱部分具有非均匀的结构，这是导致撕裂的原因之一。
分析了 15 具日本尸体的 25 个髋关节。其中 21 个髋关节进行了宏观分析，另外 4 个髋关节进行了组织学分析。在所有标本中，使用微计算机断层扫描（micro-CT）检查大转子的三维（3D）形态。在 21 个宏观分析的髋关节中，有 10 个测量了从大转子上分离的臀中肌肌腱的局部厚度。
根据髂骨起点的情况，可以大致区分臀中肌肌腱的后外侧部分。臀中肌肌腱的后外侧部分呈扇形延伸，并汇聚到大转子的上后关节面。前外侧部分向大转子的后下方向延伸至外侧关节面。后外侧部分的厚度大于前外侧部分，且这两个部分之间的边界相对较薄。组织学研究表明，后外侧部分均通过纤维软骨插入大转子。
臀中肌肌腱由厚的后外侧部分和薄的前外侧部分组成，这两个部分可以通过骨结构的关节面或方面以及其边界区域的薄度来识别。
我们的发现表明，鉴于臀中肌肌腱的非均匀结构，较薄的前外侧部分可能比较厚的后外侧部分更容易撕裂，并且撕裂通常局限于前外侧部分。
