Most people have a hip replacement because the cartilage between the bones in their hip has worn away.
A hip replacement means that the damaged hip joint is removed and replaced with parts made from biomaterials such as special metal alloys, ceramics and polymers.
In an arthritic hip, the damaged ball, or upper end of the femur called the femoral head, is replaced by a metal or ceramic ball attached to a metal stem that is fitted into the femur (with or without cement), and a plastic or ceramic liner fitted into a metal socket is implanted into the pelvis, replacing the damaged acetabulum.
Using a combination of metal or ceramic together with plastic (polyethylene), the surgeon creates a new ball and socket joint which is designed to glide smoothly and painlessly.
There are many different designs of hip arthroplasties. On the acetabular side, there are cups made out of special metal alloys to aid in fixation with and without bone screws or to be used with bone cement. On the femoral side, the type and size of the prosthetic stem is choosen by the surgeon depending on the bone quality and the age and demands of the patient.