Acetabular labrum

The acetabular labrum is a fibrocartilaginous ring which surrounds the circumference of the acetabulum of the hip, deepening the acetabulum. The labrum is attached onto the bony rim and transverse acetabular ligament. It is triangular in cross-section.
The labrum contributes to the articular surface of the joint. It embraces the femoral head, holding it firmly in the joint socket to stabilise the joint. It thus also seals the joint cavity, facilitating even distribution of synovial fluid so that friction is reduced and dissolved nutrients are better distributed.
The labrum is about 2 to 3 mm thick but is wider and thinner in the anterior portion. The anterior portion of the labrum is most susceptible to an acetabular labrum tear.