DePuy Metal-on-Metal Hips Failing in Nearly a Third of Patients: Report

According to information from a British database that tracks hip replacement problems in that country, a staggering number of recalled DePuy ASR metal hip implants are failing within six years. 

Data from the National Joint Registry for England and Wales indicates that 29% of patients who received the DePuy metal-on-metal hip replacement have reported that they failed after only six years of use.

DePuy Orthopaedics, a division of Johnson & Johnson, issued a DePuy ASR hip recall last year, indicating that about 12% to 13% of these hips mail fail within five years.

More than 90,000 DePuy ASR XL Acetabular Systems and DePuy ASR Hip Resurfacing Systems were sold worldwide before the metal-on-metal hip implants were recalled in August 2010. About 40,000 of those were sold in the United States.

The manufacturers have suggested that they have doubts that the rate could be as high as the British registry is calculating for failure at six years. However, even the registry’s five year failure rate numbers are higher than the manufacturer’s estimates, with 17% of British ASR hip recipients reporting failures.

Johnson & Johnson currently faces more than 1,000 DePuy metal-on-metal hip lawsuits that have been filed by patients whose devices failed or who have suffered metallosis, a form of blood poisoning caused by cobalt and chromium shed by the metal devices in their bodies. Some experts have estimaed that Johnson & Johnson may ultimately pay out more than $1 billion in liability over the defective hip devices.

Earlier this summer, it was reported that Johnson & Johnson has bulked up its liability fund by $570 million to cover the cost of DePuy ASR settlements.

The problems with metal-on-metal hip replacements are not limited to the recalled DePuy ASR implants, according to the registry data. All hip implants that feature metal-on-metal designs appear to have a higher failure rate than other types of artificial hips.

A hip implant is supposed to last an average of about 15 years. However, many all-metal hip replacement systems are failing much faster, causing crippling injuries, metal blood poisoning and often requiring revision surgery to have the devices replaced.

Metal-on-metal hip replacements, which use cobalt and chromium in their construction, accounted for about one-third of the 250,000 hip replacements performed in the United States in recent years. However, concerns over metal-on-metal hip replacement poisoning have caused many doctors to move away from the devices in recent months.

According to the registry, all types of hip implants, including combinations of ceramic, plastic and metal, have only a 4.7 percent failure rate after seven years. Metal-on-metal hip implants have a failure rate of 14 percent.

As the metal hip replacement parts rub against each other, microscopic particles of cobalt and chromium may be shed into the body, which can result in metal poisoning, also known as metallosis. This may result in soft tissue damage, inflammatory reactions, bone loss, genetic damage, asceptic fibrosis, local necrosis or other problems that may lead to the need for a risky hip revision surgery.

The FDA has requested metal hip manufacturers to provide more data on metal poisoning and metal implants.