Total Hip Replacement

II. What is Arthritis of the Hip?
The hip joint is a deep ‘ball and socket’ joint that connects the leg to the pelvis. Confusion about the location of this joint is common. In common everyday usage, the term “hip” is applied to a bony ridge in the pelvis which is more accurately termed “iliac crest”, (eg., I carried the baby on my “hip”).

The hip is actually a joint that is located much lower. It can be found in the location of the groin crease where the leg attaches to the pelvis.



The ball of the hip joint is the “femoral head” which rests within the socket “acetabulum” of the pelvic bone. The surface of both the ball and socket is covered with a 3-4 millimeter thick layer of cartilage.
The cartilage that lines the hip is an exceptional material. It is smoother than any man-made bearing. The cartilage has no nerve endings in it and, therefore, any motion between cartilaginous surfaces does not cause pain. In a patient with arthritis, the cartilage wears away, debris is generated producing pain. As the cartilage wears away, bone becomes exposed. The underlying bone does have nerve endings in it and is not a good bearing material. Motion between bones without cartilaginous surfaces usually causes significant pain.

Normal Hip



Arthritic Hip