Hip Failure More Likely In Women

Hip replacements in women are far more likely to fail than when a similar procedure is performed on a man, according to data analyzed by Kaiser Permanente's Southern California division.

Kaiser studied 35,000 non-emergency hip replacements performed at its facilities in Southern California between April 2001 and the end of 2010, using its own electronic medical records for analysis.

Researchers discovered that women who received hip replacements experienced failures of the device in the short term at a rate 29% greater than their male counterparts.

The overall failure rate was 2.3% for women, compared to 1.9% for male patients.

“Patients' sex has become a pressing issue in orthopedics, particularly given the anatomical differences between males and females, such as the size of the pelvis and acetabulum, or socket and head of the hip

joint,” said study lead author Maria C.S. Inacio, M.D., an epidemiologist with Kaiser Permanente's surgical outcomes and analysis unit. “Additionally, because total hip replacements are performed more often

n females, it is imperative that we understand the association between implant failure and whether a patient is female or male.”

Osteoarthritis is the leading cause for hip replacement surgery, and figures from the Centers for Disease Control and Prevention indicate women develop the condition at a rate about 40% higher than men do.

Kaiser’s data is particularly compelling for the medical community given the recent media attention that has focused on the failures of some hip replacement procedures. 

According to internal records involving biomedical giant Johnson & Johnson, as many as 40% of its hip replacements fail within five years of being implanted.

Altogether, about 285,000 hip replacements are performed each year in the United States, according to data from the Agency for Health Care Research and Quality. 

The findings also discovered that women were twice as likely to experience a hip failure when a metal-on-metal replacement is implanted than were men.

Data suggested that the requirement for smaller implants for women may be one of the reasons for the higher failure rate – their design may lead to a larger likelihood of dislocation.

“Our study will allow patients to make more informed decisions when discussing hip replacements with their physicians,” Inacio said.

The data was published in the most recent issue of the journal JAMA Internal Medicine, a publication of the American Medical Association.