In August, DePuy Orthopaedic issued a worldwide recall of the ASR XL Acetabular System, a hip socket used in traditional hip replacement, and the ASR Hip Resurfacing System, a partial hip replacement that involves placing a metal cap on the ball of the femur. Only the ASR XL Acetabular System was approved for use in the US. The recall was issued after data from the National Joint Registry of England and Wales showed that 1 out of every 8 patients (12%-13%) who had received the recalled devices had to undergo revision surgery within five years of receiving it. A hip implant should last for 15 years or so.

The recall followed a warning DePuy issued in March 2010 regarding the same implant. In a letter, DePuy warned 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 patient. According to the letter, patients of small stature, a group that typically includes women and patients with weak bones, faced the highest risk.

DePuy was already phasing out the ASR hip implant system when it finally acknowledged in March 2010 that the device was prone to early failure. By that time, the US Food & Drug Administration (FDA) had received hundreds of reports describing premature failure of the DePuy ASR hip implant system. Still, it would be months before the DePuy ASR hip implant system was finally recalled.

It is believed that many of the Depuy hip replacement complications are caused by wearing of the metal components, which can allow metal shavings to make their way into patients’ bloodstreams. The resulting cobalt poisoning could increase the risk of a number of health problems, including dementia and heart failure. DePuy now recommends that implant patients have a blood test to check for high levels of chromium and cobalt.

According to her complaint, Jo-Anne Scharf of Nova Scotia received her implant in April 2005 and was informed of the recall on Dec. 12, 2010, said the lawsuit. She is “concerned about the possibility of an early revision surgery and her blood ion levels as a result of her DePuy hip implant,” it said.

“The defendants were aware of many complaints made to the Food and Drug Administration in the United States and Health Canada regarding the failure of the DePuy implants. These complaints included component loosening, misalignment, dislocation and fracture, and the creation of abnormal or excessive metal debris in the hip socket. This metal debris could spread to surrounding tissue, causing severe inflammation and damage. The failure of the DePuy implants often requires complicated, expensive and painful revision surgery to correct.”

While the recall was only issued in August, there is evidence to indicate that DePuy had been receiving reports for several years regarding early failures of the ASR hip implant. According to a report on the Independent, a UK media outlet, the Australian Joint Registry – the second largest database in the world after the England and Wales National Joint Registry – issued seven reports to DePuy starting in 2007 that identified problems with the hip implant system. The ASR system was finally withdrawn from the Australian market in December 2009.

“The defendants, however, consistently failed to disclose or warn Canadian patients of the significant risk of failure of the DePuy implants,” Scharf’s lawsuit claims.

According to her statement of claim, Scharf wants to bring a class action on behalf of all Nova Scotians who got DePuy hip implants from July 2003 onward.