An advisory committee meeting convened in June by the Federal Drug Administration (www.fda.gov) is expected to provide the agency with guidelines for monitoring patients who have received metal-on-metal hip implants. The 18-member panel came together in Washington, DC to review scientific and clinical data regarding the troubled metal hip implant devices.

Over the past several years, the FDA and other organizations worldwide have called into question the safety of metal hip implants in response to complaints of early failure and metal ion exposure. The FDA, which gathers reports of adverse events involving metal hips, received more than 16,800 complaints between 2000 and 2011. In 2010, Johnson and Johnson was forced to issue a recall for a metal hip implant device manufactured by their DePuy Orthopedics division.

With an aging population, hip replacement surgery is one of the most common surgeries performed in the United States. It is estimated that over 500,000 patients have received the metal-on-metal version of the implant. The metal devices were thought to be a safer and more effective alternative to traditional implants which use plastic or ceramic coatings. Early evidence suggested the metal devices would last longer and cause fewer dislocation issues.

However, the longer-lasting claim of device manufacturers has been disproven with a review of recent data. With more than 6 percent of patients who receive metal hip implants requiring a second revision surgery after only 5 years being reported in some countries, these claims appear to be incorrect. Traditional ceramic or plastic implants have proven to remain functional for 10 to 15 years. Recently, due to the availability of safe, effective alternatives some countries, including the United Kingdom have recommended that metal hip implant devices not be used at all.

An additional complication can also develop from friction between the metal components that can cause the devices to breakdown early. This friction, which is a normal part by everyday activities such as walking or running, allows metal ions to wear off and eventually enter the bloodstream. Numerous reports of metal ion exposure have been received by the FDA.

Patients experiencing hip replacement failure face the possibility of invasive and risky hip revision surgery which involves removing or replacing the implant. Those patients with metal-on-metal implants have been reported to require revision surgery up to four times more often than those with traditional plastic or ceramic implants.

The FDA is expected to issue release additional information on the advisory committee’s recommendations.

http://www.bloomberg.com/news/2012-06-25/regulators-ask-for-help-to-better-monitor-metal-hip-implants.html