Capsular and pericapsular hip anatomy
Overall hip joint stability is anatomically determined by an interplay of both dynamic and static components. In the past decade research has continued to evolve our understanding of the hip capsule demonstrating the complex interaction of several key muscles and their role in capsular stability. With this in mind the authors of the present study sought to characterize our current understanding of hip capsular and pericapsular anatomy.
Following investigation the authors concluded that pericapsular contributions from several muscles (iliocapsularis, gluteus medius, and reflected head of rectus femoris) were integral in dynamic stability whereas static stability was a result of hip capsular ligaments thickest posterosuperiorly and posterolaterally at the acetabulum and anteriorly at the femoral insertion.
A cadaveric investigation was carried out on eleven non-paired hemi-pelvises with a mean age at time of death of 72 years old. Dissection was performed by two independent observers. Muscles were dissected off their origin and reflected distally toward their insertion. Capsular contributions were defined as adhesions between the muscle and hip capsule that could not be freed by blunt dissection.
An updated knowledge of the intricate relationship of the pericapsular and capsular structures is essential in guiding our treatment of the hip. Following dissection the authors were able to discern that the iliocapsularis, indirect head of the rectus, conjoint, obturator externus and gluteus minimus all have consistent capsular contributions whereas the piriformis did not have a capsular attachment.
When considering the ligamentous tissue, it was shown to be thickest at the acetabular origin in the superoposterior quadrant and anteriorly on the femur. Taken together, a current perspective of hip joint stability and its anatomy is useful when considering management of both operative and non-operative hip pathology.
> From: Walters et al., Arthroscopy 30 (2015) 10. All rights reserved to Arthroscopy Association of North America. Click here for the Pubmed summary.