Genes Can Predict Hip Replacement Success

Finding may lead to new treatments and better artificial hips, experts say.

By Steven Reinberg
HealthDay Reporter
Thursday, March 15, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

THURSDAY, March 15 (HealthDay News) -- Variations in two of a patient's genes may dictate whether or not a hip replacement will fail them over the following 10 years, new research shows.

"I don't think that there will be any immediate changes in our surgical practice, but eventually such genetic factors will have to be taken into account in our surgical planning," said Dr. Samuel J. Chmell, an associate professor in the department of orthopedic surgery at the University of Illinois in Chicago.

Chmell was not involved in the study, which is published in the March 15 issue of the Annals of Rheumatic Diseases.

According to the study's British authors, mutations in the matrix metalloproteinase 1 ( MMP1) gene and variations in the vitamin D receptor gene significantly increase the risk that a hip replacement will fail in the decade following surgery.

Knowing who has the genetic variation may help doctors predict which patients are likely to have serious problems after hip replacement surgery, lead researcher Dr. Hammad Malik, from the Centre for Integrated Genomic Medical Research at the University of Manchester and colleagues noted.

His team found that patients with variations in MMP1 are more than three times as likely to have aseptic loosening, a condition in which the artificial joint comes loose and the surrounding bone begins to dissolve, compared with those who did not have the variation.

Malik's group also found that patients with variations in the vitamin D receptor gene were almost two times more likely to encounter bone dissolution and deep infection.

"There are unknown biological factors involved in these problems," said Dr. Mark H. Gonzalez, a professor of orthopedic surgery at the University of Illinois at Chicago who was not involved in the study. "This study shows an association between aseptic loosening and MMP1. This is a very interesting association, and an understanding of this association may allow us to identify patients who are at risk for aseptic loosening."