DePuy Issues Warning on Hip Implant Device

DePuy Orthopaedics, a unit of Johnson & Johnson, warned last week that its ASR artificial hip implant appears to have a high early failure rate in some patients. This warning came months after DePuy announce it was phasing out the ASR for declining sales.

According to a report in The New York Times, the warning from DePuy followed more than two years of reports that the device was failing in patients only a few years after implant, requiring costly and painful replacement operations.

DePuy sells the ASR for use in hip “resurfacing,” a popular alternative to traditional replacement. The company also separately markets an ASR component — its hip socket, or cup — for use in traditional hip replacement. According to the Times, the Food and Drug Administration (FDA) has not approved the ASR for sale in the United States. In 2005, however, the FDA cleared the ASR cup for use in traditional hip replacement. The device was cleared through a process that did not require it to undergo clinical trials.

In a letter dated March 6, 2010 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.

The Times is reporting that since the beginning of 2008, the FDA has received about 300 complaints on the ASR involving patients in the U.S who received it, the Times said. Most of those patients underwent an operation to have the device replaced soon after getting it.

An official with DePuy told the Times some problems with the ASR had arisen because doctors were improperly implanting the device’s cup when first using it. But some doctors believe the ASR – which has a more shallow cup than similar devices – has a design flaw, something DePuy denies. However, the co-developer of the ASR told the New York Times that he and DePuy officials realized within the last two years that the ASR cup might be more of a challenge to implant properly than competing cups.

According to The New York Times, in early 2009, DePuy sent a brochure to doctors on the importance of proper cup positioning for all hip implants. But the information did not address any specific concerns about the ASR. In its March 6 letter, DePuy emphasized the need to properly position the ASR.