Metal Artificial Hip Problems Lead to Calls for Congressional Investigation

A group of U.S. lawmakers are calling for an investigation into a growing number of reported problems with metal-on-metal artificial hips, which are causing consumers to experience early failure of their implant and other complications associated with blood poisoning from the metal hip replacement systems.

Democrats on the House Energy and Commerce Committee wrote a letter to several Republican chairmen on October 12, calling for an investigation into metal hip replacement systems, as well as certain brain stents that have recently been associated with problems.

In the first six months of this year, the FDA received more than 5,000 complaints involving metal artificial hip complications from doctors and patients.

The lawmakers are also calling for an investigation into problems with the Wingspan brain stent, which were discovered during a study that was stopped earlier this year. The study compared the effectiveness of the brain stent to Plavix and aspirin, but it was brought to a halt after almost 15% of test subjects had a stroke or died within the first month of having the stent implanted.

“Both items are examples of devices that were found to be associated with major health problems after being approved or cleared by the FDA,” committee Democrats wrote. “As such, we believe they could provide important lessons about the device clearance and approval process as well as the adequacy of our postmarketing safety system.”

A few years ago, metal-on-metal hip implants accounted for about one-third of the 250,000 hip replacements performed each year in the United States. However, over the past two years, concerns have increased about the risk of metal hip replacement complications, resulting in use of the implants dropping to just 5% of the artificial hip market.

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.

In May 2011, the FDA requested artificial hip manufacturers to provide more data on the risk of metal poisoning from hip replacement implants.

The Wingspan brain stent was approved in 2005 by the FDA and was supposed to be a more effective way of opening up blocked arteries in the brain after a stroke. It was hoped that the devices would prevent future strokes more effectively than blood thinners. However, not only did a large number of patients experience strokes and death, but results from the aborted study found that it was less effective at preventing them than Plavix and aspirin.

House Democrats said that the two devices were indications of problems with the FDA’s approval process and urged Republicans to hold hearings on their approval and on recent recommendations by the Institute of Medicine, which called for an end to FDA’s 510(k) accelerated approval process, which fast-tracks medical devices onto the market without clinical testing.