Acetabulum

SkeletalSkeletonPelvisLeft and right

View left in 3D View right in 3D

What it is

Deep cup-shaped socket on the outer hip bone, formed where the ilium, ischium and pubis fuse (the triradiate cartilage in children).

Function

Holds the femoral head in the hip joint, facing outward, downward and forward.

Size

≈ 5–5.5 cm across, 2.5–3 cm deep

Clinical note

Shallow acetabula (developmental dysplasia of the hip) are screened for in newborns.