Hip Replacement More Painful for Women

Women have more problems with hip replacement surgery than do men. That is the conclusion of a study of more than 35, 000 cases of artificial hip implants by Maria Inacio, an epidemiologist with Southern California Permanente Medical Group in San Diego, California. Inacio conducted the study over a period of three years and found that the all-cause failure rate for women was 2.3% compared with 1.9% for men. About 57% of the patients in the study were women whose mean age was 65.7 years compared to 63.8 years for men.

Data for the study came from the Kaiser Permanente system’s registry of total joint replacements from 2001 to 2010. Procedures were performed at 46 hospitals in California, Hawaii, Oregon, Washington, and Colorado by 319 different surgeons. The researchers reported the results of their study online in JAMA Internal Medicine.

“One of the main reasons for failure [in women] is dislocation, and this can lead to a revision surgery, ” Inacio said. The risk appeared most prominent for aseptic revision compared with septic failure the researchers found. Larger femoral head sizes appeared especially problematic for women. For head sizes of 36 mm or more, the adjusted HR for failure in women versus men was 1.49 (95% CI 1.14 to 1.95), whereas differences in revision rates for smaller head sizes were not significant after adjustment.

John Gever, Senior Editor, MedPage Today noted, that preferences for fixation types also differed between men and women, with hybrid methods more common in the women and cementless fixation more common in men.

Delthia Ricks, writing about the study for Newsday, reported that the patients studied had received implants made from a variety of materials, including metal-on-polyethylene, ceramic-on-polyethylene; ceramic-on-ceramic, ceramic-on-metal and metal-on-metal. The metal-on-metal device was implanted least frequently in women but tended to cause the most problems, Inacio said.

Another similar study, reported by Ricks, was by Geoffrey Westrich, director of research at the Hospital for Special Surgery in Manhattan. In a study conducted over three years he reported, “We have tens of thousands of cases [in a database], and when I looked at our registry, we did not see that women fared worse than men in the short run.” But in a 2011 examination of 6, 000 cases, he found that women tended to wait longer before hip or knee joint replacement surgery, and that they report greater pain than do men.

In an accompanying commentary, reported by MedPage Today, Diana Zuckerman, Ph.D., of the National Research Center for Women and Families in Washington, D.C., suggested that the study’s clinical implications were relatively trivial.