Before revision: The procedure consists of placing a cap (usually made of cobalt-chrome metal), which is hollow and shaped like a mushroom, over the head of the femur while a matching metal cup (similar to what is used with a THR) is placed in the acetabulum (pelvis socket), replacing the articulating surfaces of the persons hip joint and removing very little bone compared to a THR.
After revision: The procedure consists of placing a cap (usually made of cobalt-chrome metal), which is hollow and shaped like a mushroom, over the head of the femur while a matching metal cup (similar to what is used with a THR) is placed in the acetabulum (pelvis socket), replacing the articulating surfaces of the person's hip joint and removing very little bone compared to a THR.