Hip resurfacing has been developed as a surgical alternative to total hip replacement (THR). The procedure consists of placing a cobalt-chrome metal cap, 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 patient's hip joint and removing very little bone compared to a THR. When the patient moves the hip, the movement of the joint induces synovial fluid to flow between the hard metal bearing surfaces lubricating them when the components are placed in the correct position. The surgeon's level of experience with hip resurfacing is most important; therefore, the selection of the right surgeon is crucial for a successful outcome. Health-related quality of life measures are markedly improved and patient satisfaction is favorable after hip resurfacing arthroplasty.
The potential advantages of hip resurfacing compared to THR include less bone removal (bone preservation), a reduced chance of hip dislocation due to a relatively larger femoral head size (giving the patient has an anatomically correct femoral head size), and easier revision surgery for any subsequent revision to a THR device because a surgeon will have more original bone stock available The potential disadvantages of hip resurfacing are femoral neck fractures (rate of 0–4%), aseptic loosening, and metal wear. Due to the retention of the patient's complete femoral neck other advantages exist: Surgeon induced discrepancies in leg length (as could happen with THR) are now minimized. Also, the toe-in or toe-out faults that could occur interoperatively with THR are now over because the femoral neck that determines foot direction is left undisturbed with hip resurfacing.