Part or all of the hip joint may be replaced:

Partial hip replacement (hemiarthroplasty): When the top (head) of the thighbone (femur) is badly damaged, it may be replaced with an artificial part (prosthesis), made of metal.

Total hip replacement (total hip arthroplasty): Sometimes the surface of the socket into which the head of the thighbone fits (forming the hip joint) must also be replaced. The socket is replaced with a metal shell lined with durable plastic.