Hip Anatomy
The hip is a ball and socket joint. The socket is the part of the hip bone called the acetabulum, and the head of the femur is the ball. Articular cartilage covers both the ball and the socket and functions to reduce friction for smooth joint movement. The labrum is a ring of very strong fibrocartilage (like a rubber band) that lines the outer edge of the socket and deepens the hip socket.
The labrum plays an important role in maintaining normal hip function. It functions to tighten the seal between the bones for joint stability, allows for a wide range of motion, and helps to maintain the alignment between the bones. In a normal, healthy joint the ball fits tightly to the acetabulum. When the bones are abnormally shaped, they can rub against each other and damage the joint.
