Osteoarthritis is at least partly caused by wear and tear and old injuries related to active recreational life. When the hip joint wears out to the point that daily activities become difficult and painful, the eventual solution is a total hip replacement (THR).   An alternative to a total hip replacement is hip prostheses. 

Hip prostheses are becoming increasingly complex, but they do not last nearly as long as a natural hip. And since a second replacement procedure is riskier and more difficult to perform than the first one, doctors often advise patients under age 65 to wait as long as possible before having hip replacement surgery. Hip resurfacing is a major surgical procedure not so different from that of total hip replacement, and there are possible problems and risks associated with it. But for well-selected patients, it may offer a good alternative and perhaps a way to shorten the wait.

The hip is a ball and socket joint–with the ball-shaped head of the thigh bone (femur) fitting within the cup-shaped socket. For a total hip replacement, the surgeon removes the entire head of the femur and replaces it with a prosthesis that is attached into the remaining portion of bone. A cup-shaped prosthesis is then fitted into the socket. One popular design uses a metal ball that fits inside a polyethylene cup.

For hip resurfacing, the surgeon merely shaves the head of the femur and covers it with a rounded metal cap. A metal cup is then fitted into the socket.

This type of prosthesis requires a more precise fit between the ball and the socket. And since less bone is cut away, the surgeon has less room to move. As a result, a larger incision may be required and the procedure often takes a bit longer to perform. It is more likely to lose more blood, and a longer recovery is needed because of the larger incision.  The major advantage is that less bone is removed from the femur, improving the chances of having a successful total hip replacement in the future. In this sense, resurfacing may be considered a way of delaying, rather than replacing, total hip replacement.

Some patients who have had both procedures (THR in one hip, resurfacing in the other) say that resurfacing feels more natural. But there is no scientific evidence to that effect.  In addition, the risk of dislocation is much less with the resurfacing procedure, and the rehab is usually shorter and less eventful.

One or two patients of every 100, however, suffer from a fracture of the femoral neck, a thinner part of the thigh bone just below the head, within the first four months. Sometimes this can be repaired; otherwise, a total hip replacement can be performed at that time. This risk of fracture is the primary reason the procedure is not recommended for elderly persons or those with osteoporosis.

The second major risk involves metal ions that are produced by the friction of metal against metal. These are potentially toxic but may be safely excreted by as long the kidneys are working properly.

Lastly, the procedure is too new for long-term results to be available regarding how safe the new prostheses are or how long they can be expected to last. However, for the past decade or so, doctors in Europe have been successfully using resurfacing procedures that have recently been reviewed and approved by the FDA.

At this time, about 400 to 500 surgeons in the United States have formal training in hip resurfacing. As with any procedure, it is important to have it performed by a surgical team that has extensive experience with the procedure.

Highly active persons are bound to be excited about anything that promises them a chance to return to their tennis, volleyball or running. Unfortunately, for high levels of activity, there is no substitute for natural hips–at least for the first year or so.

Seniors in their 50s (and some in their 60s) with sound bones may find hip resurfacing a good option to ease pain, allow them to exercise again and delay or avoid the need for total hip replacement.

 

By:  Kerri Musselman, Pharm.D.