Abstract
The evaluation and proposed relevance of acetabular labral tears has rapidly evolved
over the last decade due to the recognition of femoroacetabular impingement, an increase
in the number of surgical options, and improved imaging of the hip with MR arthrography
and 3-T MR protocols. The acetabular labrum, stabilizing the hip joint, provides a
seal, enhancing fluid lubrication, maintains synovial pressure, and prevents direct
contact of the articular surfaces. The labrum takes on a weightbearing role at the
extremes of motion with excessive forces seen in a great number of athletic activities
thought to contribute to tearing. Approximately 25% of labral tears are not associated
with any specific injury or traumatic event with the underlying etiology thought to
be repetitive microtrauma. This article reviews the anatomy of the acetabular labrum
and discusses the five most commonly occurring etiologies of labral tears: trauma,
femoroacetabular impingement, hip hypermobility, dysplasia, and degeneration. We also
review the surgical and MR classification of labral tears and describe potential pitfalls
in image interpretation.
Keywords
hip - MRI - MR arthrography - labrum
