The zona orbicularis is a circular band of hip capsular fibres that encircle the femoral neck like a collar, formed by the deep circular fibres of the three hip ligaments. It provides a secondary containment mechanism for the femoral head within the acetabulum, supplementing the bony containment and labral seal. Its tightening in hip flexion contributes to the ischiofemoral impingement mechanism.
| Origin | Circular fibres arising from the iliofemoral, ischiofemoral, and pubofemoral ligament fibres that encircle the femoral neck |
|---|---|
| Insertion | Encircles the femoral neck — not a separate bony attachment but a circularly arranged thickening of the capsule |
| Actions | Maintains femoral head containment; prevents excessive distraction of the femoral head from the acetabulum |
|---|
The zona orbicularis is visualised on hip MRI arthrography as the circular low-signal band around the femoral neck. Its surgical division during hip arthroscopy peripheral compartment access allows complete assessment of the femoral head and neck. Insufficient zona orbicularis release prevents adequate access to the peripheral compartment for cam osteoplasty.
Zona orbicularis division during hip arthroscopy required for access to the femoral head-neck junction for cam FAI osteoplasty.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
