The labrum is a tough, fibrous ring of cartilage that lines the rim of a joint socket, helping to deepen the socket and stabilize the joint. The two most commonly discussed labrums in medical imaging are the glenoid labrum of the shoulder and the acetabular labrum of the hip. On ultrasound, the labrum appears as a triangular, hyperechoic structure at the edge of the joint. Tears or degeneration of the labrum can cause pain, clicking, and instability, and sonography can help identify some of these injuries, particularly in the hip when evaluating infants for developmental dysplasia.
Sonography Term