What is Metal Hip Resurfacing?

Like total hip replacement, metal hip resurfacing is used primarily in the management of hip osteoarthritis. Metal hip resurfacing uses a bone preserving implant that is highly resistant to wear. In addition, the implant is impact and dislocation resistant. Metal Resurfacing is usually recommended for younger and very active patients who have failed non-surgical treatment.

What are the differences between metal hip resurfacing and conventional total hip replacement?

During a total hip replacement, the femoral head (ball of the hip) is removed and a stem implant is placed into the central part of the upper thigh bone (femur). A ball component is attached to the stem and the ball moves within the prosthetic socket (acetabulum).

In Hip Resurfacing, the femoral head bone is preserved and bone in the upper thigh is not violated. As the name implies, hip resurfacing involves removing the arthritic joint cartilage and re-lining the joint surfaces with metal prosthetic bearing surfaces.

What are the advantages of Metal Hip Resurfacing?

The main advantage of a metal hip resurfacing compared to a conventional total hip replacement is bone preservation. In theory, if a revision surgery is required sometime in the future, having more virgin bone to work with will make revision surgery easier to perform. This is particularly attractive in young active patients who are more likely to wear their joint replacement and require more surgeries in the future. In essence, hip resurfacing is considered to be a less aggressive first step.

Many studies that compared metal hip resurfacing to total hip patients demonstrated significantly higher activity scores in the resurfacing patients as compared to the total hip patients. This may be due to the type of patient selected for this procedure or to the more anatomic preservation of the hip joint the metal resurfacing procedure allows.

One other inherent advantage of metal resurfacing is that the incidence of dislocation is much lower as compared to conventional total hip replacement.

What are the disadvantages of metal Hip Resurfacing?

One disadvantage of metal hip resurfacing is that if it is performed in the wrong patient, it will likely not have a good outcome. People with severe hip deformity or reduced bone strength due to cysts or osteoporosis should not undergo this procedure. Also, there is a minimum size requirement for metal hip resurfacing procedures. Metal hip resurfacing is not meant for people with a small femoral head size. Unfortunately, many women’s femoral head size is below the threshold and thus they are not good candidates for metal hip resurfacing.

Traditionally, metal hip resurfacings use Metal-on-Metal bearing surfaces. While this bearing has a very low wear rate and is impact resistant, a small number of people may develop a reaction to this type of bearing and the metal ions that are produced. The incidence of this reaction in modern metal hip resurfacing is rare in appropriately selected candidates but monitoring is usually recommended. If metal hip resurfacing is desired, then the merits of this implant in comparison to alternative prosthetic designs will be discussed with you in detail.

Who is suitable for metal Hip Resurfacing?

The ideal candidate for metal hip resurfacing is a larger framed male less than 60 years of age with severe hip osteoarthritis.

Are there recent advances that might address some of the shortcomings of metal Hip Resurfacing?

More recently, ceramic hip resurfacing has become available for the management of advanced hip osteoarthritis. These implants have been in clinical use since 2018 and therefore the long-term clinical results are not yet known. Until longer term performance data is available, the use of these new implants is performed under specific situations and close monitoring.