Study: DePuy Hip Implants Fail More Often in Women

Women are more likely than men to undergo a second hip replacement, particularly after receiving an implant made by DePuy Orthopaedics Inc., according to data from the National Joint Registry of England and Wales.

Twelve percent of patients with DePuy’s hip resurfacing system and 13 percent of those with the firm’s acetabular system needed corrective surgery, the data showed. And, there is proof that a patient’s hip size can determine the frequency of revision surgery: A study conducted by the University of Adelaide in Australia concluded that the risk of revision is highest in patients with ASR femoral head sizes below 50 millimeters in diameter. Such sizes affect mostly female patients.

Joint replacement registries in both Australia and the United Kingdom have recorded higher than expected complications with DePuy’s ASR Hip Resurfacing System and ASR XL Acetabular System total hip replacement, including a loosening of the implant within the body, bone fractures near the implant, dislocation and a condition called metallosis, which occurs from the rubbing of metal parts.

The growing number of patients needing a second hip replacement prompted Johnson & Johnson’s DePuy Orthopaedics unit to recall its ASR XL Acetabular System, a hip socket used in traditional replacement surgery, and the ASR Hip Resurfacing System, a partial hip replacement that involves placing a metal cap on the ball of the femur in order to preserve more bone. The company announced the recall on Aug. 26, 2010.

About 93,000 ASR devices have been implanted in patients worldwide, according to DePuy. And while the recall may have come as a surprise to some patients, experts have claimed it was inevitable, saying failure rates and patient complaints doomed the device. Over the last two years, the FDA has received about 400 complaints from American patients who received the implants, according to a March 2010 article in The New York Times.

In late 2009, DePuy said it was phasing out the implants due to slowing sales. Last March, the company warned doctors that the implants might have a high failure rate in some patients. In a letter dated March 6, 2010, DePuy told doctors that recently analyzed data from Australia suggested that the ASR had a higher-than-expected failure rate when used in traditional hip replacement on certain types of patients. The letter said the data shows that the risk is highest for patients of small stature, a group that typically includes women, and patients with weak bones.

Many hospitals that specialize in joint replacement surgery had already noticed a higher failure rate with the DePuy hip implants, Joshua J. Jacobs, M.D., chairman of orthopedic surgery at Rush University Medical Center in Chicago, told the Times. “Most major medical centers have seen issues with this device. This does not come as a surprise,” he told the newspaper.