Genes may Predict Hip Replacement Woes

Ivanhoe Newswire
Friday, March 16, 2007; 12:00 AM

(Ivanhoe Newswire) -- Why do some people have problems with hip replacements while others slide by with no worries?

Researchers in England suggest it all may lie in the genes. Their study identified two genetic variations associated with loosening of the bone around the artificial joint and infection near the implant.

For the study, researchers compared genetic profiles of 312 people who had undergone a hip replacement in the past 10 years. About half experienced problems with dissolution of the bone or deep seated infection around the implant. The average time until problems arose with bone dissolution was about five years from the initial surgery. One average, infections were seen less than a year later.

Researchers linked bone dissolution with variations in a gene responsible for making an enzyme responsible for breaking down collagen, the main component of bone and cartilage. Both bone dissolution and infection were more common among people with a genetic variation in a vitamin D receptor gene. Vitamin D is essential for bone health.

Variations in another gene responsible for making a chemical involved in bone metabolism didn't appear to affect hip replacements one way or the other.

The authors note many people do experience excellent results from hip replacements, but "long-term failure of these implants due to loosening and associated bone loss remains a problem." They plan follow up studies to see how these particular genes might be putting people at risk for poorer outcomes.

This article was reported by Ivanhoe.com, which offers Medical Alerts by e-mail every day of the week. To subscribe, click on: http://www.ivanhoe.com/newsalert/.

SOURCE: Annals of the Rheumatic Diseases, published online March 14, 2007