The acetabulum is formed by the fusion of three pelvic bones: the (upper portion), the ischium (posterior/lower portion), and the pubis (anterior/inner portion). These bones are initially separated by a Y-shaped triradiate cartilage that typically fuses completely between the ages of 20 and 25. Key anatomical features include:
: A horseshoe-shaped area covered with hyaline cartilage known as the lunate surface . acetabulum
: A central, non-articular depression that contains a fat pad. The acetabulum is formed by the fusion of
: A fibrocartilaginous ring attached to the rim that increases the depth of the socket and improves joint stability. the ischium (posterior/lower portion)