Current regulations allow devices, including hip implants, to be cleared under the agency's expedited 510(k) process rather than the more rigorous pre-market approval pathway. The 510(k) process is reserved for devices deemed “substantially equivalent” to another product on the market.
“It's a really important move by FDA to give more weight to approval of metal-on-metal hip implants,” said Lisa McGiffert, director of Consumers Union's Safe Patient Project. “We hope this is a signal that the FDA might be starting to look at the (other devices) that appeared to have been grandfathered in to the 510(k) process.”
Metal-on-metal hip implants have higher failure rates than other hip implants. Metal released by these implants can damage a patient's bone or soft tissue, which can lead to loosening of implants, device failures, revision surgeries and elevated metal ion levels.
Johnson & Johnson's DePuy Orthopaedics business recalled 93,000 metal-on-metal hip implants in 2010 and was hit with thousands of lawsuits in the wake of the recall. Zimmer and Smith & Nephew also recalled metal-on-metal implants or related components.
The FDA received authority last year in the industry user-fee agreement legislation to reclassify devices by order rather than by regulation.
“That is absolutely and exactly what we're hoping for,” said Diana Zuckerman, president of the National Research Center for Women & Families. “This experience, with metal-on-metal hips, should have taught all of us … that we need clinical trials for all hips.”
In addition to supporting the new requirements for pre-market clinical trial data, physician organizations and patient groups have called for a stronger post-market surveillance system that would include a national registry to track implantable medical devices. Registries in Australia and the United Kingdom were the first to identify problems associated with metal-on-metal hips.
“We don't have a post-market surveillance system,” said Dr. Kevin Bozic, vice chairman of the orthopedic surgery department at the University of California at San Francisco. “There is no registry, of hip or knee, on the scale that would pick up these kinds of problems.”
The American Joint Replacement Registry is one of a few registries that have been developed in the U.S. The American Academy of Orthopaedic Surgeons, which formed the AJRR in 2009, said it has enrolled 118 hospitals and gathered data on 32,000 procedures since its pilot program went into effect in March 2011.
“It's better to have the data beforehand,” Zuckerman said, “but the registries are going to provide the kind of long-term data you need.”