DEPUY ASR HIP IMPLANT INJURIES

It is believed that at least 12%, or approximately 1 in 8 patients, fitted with a DePuy ASR hip implant will require hip revision surgery. The DePuy ASR hip replacement device is made with as shallower cup than some other hip implants, which may contribute to its high failure rate. The DePuy ASR hip implant recall was issued after hundreds of DePuy device recipients in the U.S. and elsewhere reported symptoms of a failing implant, including:

• Constant hip pain
• Thigh and/or groin pain
• Pain while walking
• Weight-bearing pain
• Pain rising from a seated position
• Blood test confirming elevated levels of chromium and cobalt ions

Surgeons in Australia were reporting high failure rates in DePuy ASR hip implant patients as early as 2008. In fact, in 2009, Australia became the first country to withdraw the devices from the market. Later that year, DePuy Orthopaedics announced a plan to phase out sales of its ASR hip implants worldwide by the end of 2010, blaming lagging sales of the devices. However, DePuy blamed ASR hip replacement complications on the surgeons who had implanted the devices.

DePuy finally acknowledge problems with ASR hip implant in March 2010, when it sent a letter to doctors informing them that recently analyzed data from Australia indicated a higher-than-expected failure for certain types of patients, including women, patients with weak bones, and those of short stature. By the time DePuy finally announced the ASR hip implant recall on August 24, 2010, some 93,000 devices had been sold worldwide.

METAL-ON-METAL HIP IMPLANT COMPLICATIONS

Metal-on-Metal hip replacement devices, like the DePuy ASR hip implant, consist of a ball and cup made of chromium and cobalt. Because the metal ball and the metal cup slide against each other during walking or running, some tiny metal particles may wear off the device and enter into the space around the implant. This can cause an adverse local tissue reaction known as metallosis, which results in damage to bone and/or tissue surrounding the implant and joint. The tissue and bone damage can cause the implant to loosen, forcing patients to undergo revision surgery to have the failing device replaced.

These potentially toxic metal ions can also build up in a patient’s blood stream. Some metal-on-metal hip implant patients with high levels of chromium and cobalt in their blood have experienced symptoms or illnesses elsewhere in the body, including effects on the heart, nervous system, and thyroid gland.

A recent report from the National Joint Registry in Great Britain found that nearly 14% of patients who received a metal-on-metal replacement required revision (removal or replacement of joint) within 7 years. This is compared to only a 3% revision in patients who received a joint made of plastic during the same follow-up time.