Iliopsoas impingement may be present in both natural and artificial hips.
In the case of a natural hip, it has been theorized that because of its close relationship to the anterior hip, a tight iliopsoas tendon may be a cause of anterior labral lesions. The clinical presentation of this form of iliopsoas impingement may not be accompanied by a snapping phenomenon and have positive impingement tests, log roll and mechanical hip symptoms more in accordance with symptoms related to a labral tear.
When iliopsoas impingement occurs in presence of total hip replacement (THR), affected patients typically report persisting groin pain that is exacerbated by stair climbing, getting into or out of bed or a chair and entering and exiting an automobile. A snapping phenomenon or a clunk is usually not present. Gait may be affected with the patient presenting a slight limp. It is important to remember that the patients must first be evaluated for more common causes of groin pain after THR like infection, component loosening and occult periprosthetic fractures. A typical finding at radiographs or CT is a protruding anterior implant rim uncovered by the bony anterior acetabular wall.
Conservative treatment for both conditions (iliopsoas impingement in natural and artificial hip joints) is the same including rest, NSAIDs and physical therapy. Iliopsoas injections are of limited therapeutic value, but they represent a very reliable diagnostic test. After failure of conservative treatment, surgical release of the iliopsoas tendon may be indicated.
In the case of iliopsoas impingement with a natural hip joint, hip arthroscopy will provide access for treatment of the associated lesions such as labral tears or underlying bony impingement.
When iliopsoas impingement is present in an artificial total hip joint, acetabular component revision for re-orientation and open iliopsoas release have been reported. Both techniques seem to be effective in the treatment of iliopsoas impingement with the open release of the iliopsoas tendon presenting less morbidity. It is also possible to perform endoscopic release of the iliopsoas tendon in a THR, but reported results in the peer-reviewed literature is limited.
Endoscopic release of the iliopsoas tendon has evolved over the past decade. A variety of surgical techniques is available for release of the iliopsoas tendon at different anatomical regions.
As described from proximal to distal, endoscopic release of the iliopsoas tendon may be transcapsular at two different sites: from the central compartment and from the hip periphery. It can also be performed within the iliopsoas bursa at its insertion on the lesser trochanter. For either one of these techniques, the patient is positioned for hip arthroscopy in supine or lateral decubitus.
Iliopsoas tendon from the central compartment is performed with the hip joint in traction. The anterolateral portal, as described by Byrd at the anterior superior corner of the greater trochanter, is used as the viewing portal. With a 70° arthroscope, the anterior capsule is identified. From the direct anterior portal, a radiofrequency hook probe or an arthroscopic banana knife is introduced to create an anterior hip capsulotomy relative to the 2 and 3 o’clock position of the labrum in a right hip or geographic zone 1. Fibers of the iliopsoas tendon are visualized through the capsulotomy. The tendon is further exposed using a mechanical shaver. A radiofrequency hook probe is used to release the tendon in a retrograde fashion leaving the iliacus muscle intact.
Iliopsoas tendon release from the hip periphery is performed without traction. A 70° or a 30° arthroscope is positioned into the peripheral compartment anterior and inferior to the femoral neck through the anterolateral portal. Landmarks at the hip periphery must be identified. The medial synovial fold serves as the best landmark to identify the inferior aspect of the head and neck (6 o’clock position). The proximal origin of the medial synovial fold at the inferior head-neck junction is visualized. The field of view is rotated to the anterior hip capsule. The mid anterior portal is used to introduce instruments into the peripheral compartment. Between the anterior inferior labrum and the anterior inferior zona orbicularis a capsulotomy is performed and the iliopsoas tendon fibers identified through the capsulotomy, in some cases a natural communication between the anterior hip capsule and the iliopsoas bursa is present at this level. The tendon is further exposed using a mechanical shaver. Finally, the iliopsoas tendon is released in a retrograde fashion using a radiofrequency hook probe. The iliacus muscle is left intact behind the released iliopsoas tendon.