My hip is going to be replaced but I am under 55. My doctor says that people my age who are active should have something called a partial hip replacement. Can you explain what that is?

A total hip replacement, called a total hip arthroplasty (THA) literally replaces the hip joint. The implant is attached to the bones and is set into place.

A partial replacement, called total hip resurfacing, replaces only part of the hip, which provides an advantage for many people.

With hip resurfacing, the surgeon reshapes the head (top) of the femur (thigh bone) and fits a lining over it, as opposed to the total replacement that will remove that part of the bone and replace it with an implant. With the resurfacing, the bones need to be strong and able to withstand the force of the procedure, so people who have weakened bones are not able to have this type of surgery.

The benefits to the resurfacing are that it appears to have a lower dislocation rate, the healing time is faster, and because the head of the femur is preserved, there is enough bone left for further surgery if it is needed.