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What is the acetabulum’s role in the hip joint?

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The human hip and pelvis — ball-and-socket joint Anterior view of the hip and pelvis, showing attachment of ligaments to the femur, ilium, ischium, and pubis.

The acetabulum is a cup-shaped socket in the hip bone that forms the hip joint with the head of the femur. This structure allows for the free rotation of the leg. The acetabulum is formed by the fusion of three bones: the ilium, ischium, and pubis.123