An anatomic study of the impressions on the greater trochanter: bony geometry indicates the alignment of the short external rotator muscles.

In this study, 44 hip regions from 25 embalmed cadavers were dissected to identify the bony landmarks on the greater trochanter, which indicate the individual short external rotator muscle insertions. Micro-computed tomography (micro-CT) images were obtained to identify the bony impressions on the greater trochanter. Then, the soft tissues were removed and their insertions were identified to assess correlation with micro-CT images. Bony landmarks indicating the insertions and the running course of the piriformis muscle, the obturator internus muscle, and the obturator externus muscle were identified on the greater trochanter in all specimens. These findings could be helpful for preserving muscles during capsular release in the anterior approach because the alignment of the short external rotator muscles can be estimated preoperatively using CT images.