For Women, Concerns About a Hip Device

The New York Times—November 7, 2008

Even as patients in this country continue to undergo an increasingly popular alternative to traditional hip replacement surgery, medical researchers both here and abroad are raising warning flags about the technique's use in women.

The procedure is aimed at middle-age patients, who are physically active and are expected to outlive the normal 15-to-20-year life span of a full replacement joint. Because hip resurfacing preserves more of a patient's own thigh bone than conventional full hip replacement, proponents say patients who undergo it will be better able to tolerate subsequent replacement surgery.

But studies from some countries where resurfacing has been used longer than in the United States, including Sweden and Australia, have repeatedly shown a higher failure rate for women who undergo the procedure than for men. Such women are more likely to need a second corrective operation soon after the first, compared with women who get a conventional full replacement hip, a recent British study found.

In recent years, even as hip resurfacing gained popularity here, some orthopedic specialists refused to perform it in any patient, male or female, citing a lack of long-term data about its durability.

With traditional replacement hips, "based on data, I know what the results will be in 10 to 20 years," said Dr. Thomas P. Sculco of  Hospital for Special Surgery, in Manhattan, who performs only traditional replacements. "I can't give you 10-to-20-year data for hip resurfacing."

In a traditional hip replacement, the upper end of the thigh bone, or femur, is removed and replaced with a prosthesis. In a hip resurfacing, a greater portion of the femur is saved, with an artificial cap placed over the head of the femur. Many men and women say they are pleased with the procedure's results. But when failures occur, it is because a patient's bone is not strong enough to support the device or because of surgical error.

Even surgeons who specialize in resurfacing acknowledge that there are no conclusive tests to determine which women are the best candidates. For example, while some doctors run a bone density test on a patient, there is no agreement among surgeons about what test scores should serve as a threshold.

Dr. Edwin P. Su, who practices at Hospital for Special Surgery and specializes in resurfacing, said, "There is a very narrow window for women to have a resurfacing." He described ideal candidates as women in their 40s and 50s, although he added he would perform the procedure on somewhat older women if their physical conditions warranted it.

Read the full story at nytimes.com.