With a wide array of medical device implants currently on the market, FDA regulations are essential in ensuring patient safety -- through, what are supposed to be, rigorous premarket review and postmarket surveillance processes. Unfortunately, these processes don’t always prevent harmful devices from being available to a consumer.
Implantable medical devices have evoked some concern since the first generation of hip implants hit the market in the mid-20th century. However, recent years have brought about greater scrutiny as a critical mass of adverse events reports related to medical device implants like Essure and metal-on-metal hip replacement systems has emerged.
This year, the FDA’s Medical Devices Advisory Committee, intended to make recommendations to the FDA on the safety and effectiveness of in vitro devices, set out to address the problem.
In September, the administration published a 150-page report covering adverse responses to metal-containing implants. The report explained that metal and metal alloys are commonly used in implanted devices and dental amalgam.
The statement read:
To better understand how a patient responds to materials used in medical device implants and improve the safety of a device in patients, the FDA is working to engage the public--in particular, scientists, patients, and health care providers--as well as industry stakeholders to determine the current state of the science, critical gaps in the existing science and what approaches should be considered.
A request for public comment was published on Oct. 1, and a federal docket drew more than 280 comments ahead of the meeting, with many coming from patients and patient advocates.
During the two-day meeting welcoming such perspectives, speakers reported on adverse events related to implants containing metal or metal alloys. Hip, knee, cardiac and other surgically implanted devices were all discussed by the public, with the goal of identifying further steps to assess biocompatibility for patients and subsequent research priorities.
Due to the current lack of data on medical devices, adverse events aren’t always easy to predict. The ability to screen for new types of unknown sensitivities is limited due to lack of detailing in metallic components.
Karin Pacheco, a University of Colorado in Denver allergist, said some patients with joint failure and a metal implant allergy eventually used an implant with a different type of metal component, and ended up doing well.
Pacheco had looked at data on 1,500 patients with unexplained joint failure, half of whom were sensitized to a relevant metal in a joint implant. She believes nickel, cobalt, chromium and possibly titanium were the culprits for adverse biological responses but says more research is needed.
Diana Zuckerman, president of the non-profit National Center for Health Research, emphasized the need for comparative effectiveness research in order to test out the best solutions when a patient requires a medical device implant. Moreover, because not all metal-on-metal implants are the same, they shouldn't all be approved because a single study finds one safe for use. Different models must be compared.
"If certain implants seem to be causing certain reactions with certain kinds of patients, wouldn't it be very important to know how that compares to other alternatives of the same kind of implants?” she asked.
“We can't treat all hip implants that are polyethylene and metal as if they're all the same.”
Other patients, such as Sue Francis, who has a ceramic-on-polymer hip implant, said the FDA should label implants with component materials for more effective diagnosis. It was evident that the vast majority of patients remain unaware of the materials used in their medical devices and the life-altering, biological impacts such materials can have.
Stephen Tower, for instance, an orthopedic surgeon featured in Netflix documentary, “The Bleeding Edge,” was unaware about the health risks of medical devices. As a result of his own hip implant, he suffered with necrosis and cobalt poisoning -- conditions that evoked mental fog and fits of rage. According to Tower, the problem isn’t limited to metal-on-metal hip implants. Other types of hip implants, and sterilization devices like Essure, have wreaked similar havoc.
FDA Supervisory Medical Officer Aron Yustein presented on new diagnostic tests and adaptations for more informed patient selection. He said that the FDA plans to extend its efforts to recognize risks of implants even beyond metals, and that test results alone cannot predict adverse events and may be also too expensive to single out a small sub-population.
To better track patient outcomes, the FDA may pursue a diagnostic tool that may “enable detection before a serious adverse event” while also promoting “confidence that the signal detected is real.” Current tests aren’t sufficient in providing an accurate warning.
Possible associations pointed to gender as a factor, according to Yustein, who noted that well-functioning implants can still yield abnormal test results.
He testified, “the majority of patients experience no clinically significant local or systemic adverse health effects.”
Speaking to a group of medical professionals, researchers and patients in perfect health prior to their device implant who could vouch for the invasive harm that devices had caused, Ystein added, “it may be difficult to link these reactions to the device, which may have been implanted years before and may be functioning well.”
Though much remains unclear surrounding when metal devices go from safe to life-threatening, one thing was evident: the FDA will need a better understanding of patient and product risk factors that contribute to a growing number of reported adverse device responses.
Public comment on the issue will be open until December 16. If you or someone you know has been impacted by a metal-containing medical device, comment here.
Information invites change. It's time to require stronger regulation on medical devices.