Post-market studies on metal-on-metal hip implants laggingJun 22, 2012 | Parker Waichman LLP
Post-market safety studies on metal-on-metal hip implants ordered by the Food and Drug Administration last year have been slow in getting started, according to a new report.
MedPageToday.com reports on a review conduted by Pew Charitable Trusts which found that less than one-quarter of the studies ordered by regulators have actually started and progress overall is slow. The researchers, which have published their findings online with the New England Journal of Medicine, found that most reviews slated for troublesome metal-on-metal hip implants are still in the "pending" or "overdue" status with the FDA. They say the agency needs to "change its approach" to these studies to get them started. For those studies for which the FDA has approved the protocol for the research, the report indicates it's difficult to determine if any work has actually begun.
Last May, the FDA ordered 33 makers of metal-on-metal hip implants to conduct post-market safety reviews of their medical devices to determine what, if any, benefits they give to recipients. This order came after the high-profile recall of the DePuy Orthopaedics ASR hip implant after thousands of recipients of it and other metal-on-metal hips blamed the implants for causing numerous complications, including putting them at risk of toxic metal poisoning.
When the metal components of an all-metal hip make contact with each other through normal use of the device, it can shed tiny metal particles into the bloodstream and surrounding tissues and organs of a recipient. Many who have metal-on-metal hips like the DePuy ASR have reported developing deposits of the metals cobalt and chromium in their bodies. This has led to tissue and organ damage and can lead to organ failures. Thought to be an improvement on existing implants, makers of metal-on-metal hips touted their products as longer-lasting than older models.0
Overall failures of the devices due to defective designs have also caused recipients to suffer other injuries, like pain and inflammation at the site of the implant, the need for revision surgeries and eventual replacement surgeries. A prognosis for a person receiving a defective hip implant that must be replaced due to early failures may include the loss of full mobility and a painful recovery from the follow-up surgery.
The study on the reviews indicate the FDA's guidelines have opened the door for more skepticism, especially as some manufacturers continue to contend that their devices are safe and more effective than other models. Manufacturers are permitted to conduct their own, independent studies of the devices. Inconsistencies that are likely to develop among the reviews will make it difficult to make judgements on all devices using metal-on-metal components. The study from Pew also urged the FDA to adopt a medical devices registry which would allow for more transparent tracking of device failures and for the agency to make its own determinations of the safety of devices.
Delaying these studies only helps the manufacturers to sell more metal-on-metal hip implants, potentially putting thousands more people in the U.S. at risk of these injuries.
The FDA plans to meet next week to review the progress, or lack thereof, of the ongoing or stalled studies, the report adds.