This bowl-like concavity is situated on the lateral surface of the os coxa facing antero-inferiorly. All three elements, ilium, ischium, and pubis, contribute to its structure. The fossa of the acetabulum has a smooth, lunar articular surface for the head of the femur. The inferior margin of the cup is notched, opening into the fossa. From this notched region a rough, nonarticular groove leads into the fossa for the attachment of ligaments. The articular surface is widest superiorly where the weight of the body is supported on the head of the femur.

Acetabulum is derived from the Latin acetum meaning vinegar and abulum for cup or bowl. Pliny, Celsus, and other early anatomists viewed the deep, bowl-like hip socket to resemble an open vinegar cup.

Acetabulum

Acétabulum