Acetabular fossa

The acetabular fossa is the non-articular depressed region at the centre of the floor of the acetabulum. It is surrounded by the articular lunate surface.^: 1368 The floor of the fossa is formed mostly by the ischium; it is rough^: 1354 and thin (often to the point of transparency). The space of the fossa is continuous inferiorly with the acetabular notch.

The fossa does not contain any cartilage.^: 1368 It is occupied by the ligament of head of femur, and by fibroelastic adipose tissue^: 1368 (within which the acetabular branch of the obturator artery ramifies^: 1250) that is mostly lined with synovial membrane.^: 1368 The acetabular "fat pad" is thought to contain abundant proprioceptive nerve endings that sense compression of the fat pad or its displacement through the acetabular notch, producing proprioceptive information.