Definition

By Gregory R. Waryasz, MD

The acetabular labrum of the musculoskeletal system is characterized by being attached to the acetabular rim of the socket.

It is part of the hip joint. It consists of fibrocartilage.

Its unique structural feature is that it is triangular in shape.  The labrum is attached to the acetabular rim and runs circumferentially.  The continuation of the acetabular labrum is the transverse acetabular ligament.  The blood supply is best at the peripheral portions of the labrum.

The acetabular labrum as well as all other bones, muscles, and ligaments of the body are derived of mesodermal origin in the embryo.

The function of the acetabular labrum is to increase the articulation surface of the acetabulum.  It essentially helps to hold the femoral head in contact with the acetabulum. The labrum may also play a role in maintaining synovial fluid in the hip joint.

Common diseases include labrum tears and impingement syndromes.

Labrum tears can be due to a variety of conditions including dysplasia, impingement, and trauma.

Femoral-acetabular impingement can lead to labral injury.  CAM impingment occurs during flexion, adduction, and internal rotation and is due to abnormal femoral head/neck junction anatomy. There is compression between the femoral neck and acetabular rim.  Pincer impingement is due to excessive acetabular coverage.

Commonly used diagnostic procedures include clinical history, physical exam, MRI, bone scan and CT scan.

It is usually treated with physical therapy and NSAIDs. Surgery can be performed either with a large open incision or performed with arthroscopy.

References

Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.

Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.

Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.

Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.