Musculoskeletal ImagingE3012. Attention to Other Types of Hip Impingement
Chamberlin B, Garza-Gongora R, Parman L, So C. Baylor Scott & White Memorial, Temple, TX
Address correspondence to B. Chamberlin (firstname.lastname@example.org)
Background Information: Femoroacetabular impingement (FAI) due to underlying cam- and pincer-type lesions are amply addressed clinically and in the literature as common culprits of hip pathophysiology and pain. Although less common, extraarticular types of hip impingement also serve as a source for hip pain and should be understood by the interpreting radiologist. Given the appropriate history, physical, radiographic, and arthroscopic findings, these extraarticular subtypes of hip impingement can be delineated from each other and distinguished from FAI, which will facilitate the application of an appropriate treatment regimen.
Educational Goals/Teaching Points: The goals of this exhibit are to outline the anatomy of the hip joint and the surrounding structures that can cause hip impingement, delineate the subtypes of extraarticular hip impingement, and detail the different historical, physical, radiographic, and arthroscopic findings that can differentiate causes for extra-articular hip impingement. We will also discuss management options.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: The internal components of the hip joint include the acetabulum, transverse acetabular ligament, labrum, femoral head, and the ligamentum teres. Although, imaging assessment of these intraarticular structures are essential in the workup of hip pain, the surrounding extraarticular structures also serve as sources for hip pain. Extraarticular hip impingement syndromes include subspine, ischiofemoral, iliopsoas, and greater trochanteric or pelvic impingement syndromes. Other maladies that may elicit hip pain in the minority involve abnormal femoral version and acetabular tilt. These particular diagnoses are seen more often in patients of a particular sex or age group as well as those who participate in certain hobbies and sports. Predictable degrees of hip range of motion and specific tests can be seen in individual types of hip impingement. Furthermore, there are key radiographic and arthroscopic findings for distinguishing atypical types of impingement from each other. It is important to determine the cause of a patient’s hip pain as most of these syndromes are treated differently, whether it be conservatively or with surgery.
Conclusion: Although cam and pincer lesions are well recognized and discussed, it is important for radiologists to be aware of these other types hip impingement, as the diagnosis will affect the patient’s treatment course and ultimately his or her outcome.