Hip capsular strain varies between ligaments dependent on both hip position‐ and applied rotational force. Capsular management during hip arthroscopy: From femoroacetabular impingement to instability. Arrow head, cutting line of the connection between the gluteus minimus tendon and the joint capsule Circle, inferomedial end of the intertrochanteric line Dagger, superolateral end of the intertrochanteric line Ip‐a, deep aponeurosis of the iliopsoas GMi‐a, deep aponeuroses of the gluteus minimus Labrum, acetabular labrum RF‐a, proximal deep aponeurosis of the rectus femoris Star, inferior area of the anterior inferior iliac spine Lat, lateral Med, medial Post, posterior Sup, superiorīedi, A. By evaluating the inner side of the joint capsule (b and e), the narrowest area of the articular cavity was measured perpendicular to the femoral neck (c, f: cross‐sections along lines b and e, respectively). The images on the anterior aspect of the joint capsule (a and d) correspond to Figure 1c,f, respectively. Three‐dimensional images of the joint capsule at hip extension (a–c) and flexion (d–f). Micro‐CT analysis of the joint capsule and its articular cavity at hip extension and flexion. AIIS, anterior inferior iliac spine ASIS, anterior superior iliac spine Circle, inferomedial end of the intertrochanteric line Dagger, superolateral end of the intertrochanteric line Ip‐a, deep aponeurosis of the iliopsoas GMi, insertion of the gluteus minimus on the greater trochanter GMi‐a, deep aponeuroses of the gluteus minimus RF‐a, proximal deep aponeurosis of the rectus femoris Star, inferior area of the AIIS Lat, lateral Med, medial Sup, superior Finally, the joint capsule was detached from the acetabular margin and femur, and all bony elements were removed (c and f). Second, the bony morphology of the pelvis and femur was examined using micro‐CT, and the narrowest cross‐sectional area of the neck of the femur perpendicular to its longitudinal axis were measured (b and e: white lines indicate the measurement plane). The connection between the gluteus minimus tendon and the joint capsule was cut (arrowheads). First, the pericapsular muscles were carefully removed while their deep aponeuroses connected to the joint capsule were preserved (a and d). Anterior aspects of the joint capsule at hip extension (right hip a–c) and flexion (left hip d–f). Preparation of the joint capsule for examination by removing the bony elements. Clinical Anatomy published by Wiley Periodicals LLC on behalf of American Association of Clinical Anatomists. In other words, the joint capsule could change its morphology dynamically depending on the hip position.Īnatomy hip joint joint capsule musculoskeletal system. The zona orbicularis was interpreted as the inward protrusion caused by dynamic change of the joint capsule, rather than the local collar. This inward protrusion was not histologically independent of the joint capsule. The Thiel's method specimens showed that the inner surface of the joint capsule protruded inward toward the femoral neck during hip extension.

Micro-computed tomography images revealed that the inward protrusion of the joint capsule narrowed the articular cavity, and the ratio of its narrowest area to that of the femoral neck was less at hip extension than at hip flexion. The remaining three formalin-embalmed bodies were examined histologically. During formalin fixation of six hips from these three bodies, one side was maintained at hip extension and the other at flexion. The joint capsules in three formalin-embalmed bodies were sturied by micro-computed tomography. Six and three of the donated bodies, respectively, were embalmed using 8% formalin and Thiel's method. Twelve hips from nine bodies donated to science were examined. The aim of this study is to investigate the characteristics of the inner side of the joint capsule comprehensively. Despite the proximity of the whole joint capsule to the zona orbicularis, their anatomical relationship remains unclear. The zona orbicularis, which comprises the inner circular fibers of the joint capsule, is vital for hip stability in distraction.

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