Medical Device Safety Concerns Rheumatologists

Over the years, there have been a number of highly publicized instances where medical devices allowed to enter the market were later found to fail at higher-than-expected rates. While rheumatologists don’t implant medical devices, they do have an interest in how these devices work—and that they work well—because they may recommend the use of prosthetic joints and other kinds of medical devices to their patients.

“Among the various devices coming under question in recent years, there has been a significant concentration in the orthopedic realm,” says C. Ronald MacKenzie, MD, associate professor of clinical medicine (rheumatology and medical ethics) at the Hospital for Special Surgery, the Weill-Cornell Medical Center in New York. “These concerns are therefore relevant for the patients we look after as rheumatologists.”

Three Risk Categories

Requirements that makers of medical devices notify the Food and Drug Administration (FDA) before marketing a new product were established under section 510(k) of the Federal Food, Drug, and Cosmetic Act passed in 1938. The process in place today started following passage of the Medical Device Amendments Act in 1976.

The FDA has classified medical devices into three categories, according to their level of risk. “Class I presents the lowest risk and are exempt from any type of premarket approval [PMA],” says David Challoner, MD, vice president for health affairs emeritus of the University of Florida in Gainesville. “These are things like tongue depressors. They go directly to market after their manufacturing processes are reviewed and approved.”

The middle category, Class II, is by far the biggest group, with 90% of all devices authorized for market falling under this umbrella.¹ These devices are thought to pose some risk to the consumer but can usually be marketed after submitting PMAs, called 510(k) applications after the section of the law, showing their “substantial equivalence” to another legally marketable device.

Class III devices pose the highest level of risk and must establish both safety and efficacy. This is the only level with that requirement, and generally requires PMA.

Substantial Equivalence

To understand both the reality and the concerns about the current 510(k) process, you have to understand the concept of substantial equivalence.

“Ford comes up with a new car that has an engine, four tires, seats; while there are some cosmetic differences they are not really all that different from other cars at the mechanical level,” says Matthew Kraay, MD, Kingsbury G. Heiple and Fred A. Lennon Professor of Orthopaedics, Case Western Reserve University, Cleveland. “Most devices are approved that way. You only have to point to something that was approved in the past, called a ‘predicate device,’ and convince the FDA that yours is the same as the earlier one.”

This has led to many devices never being subjected to close scrutiny by the FDA or anyone else. “Today we have a system in which a new moderate-risk device can enter the market because it is substantially equivalent to another device that may have been cleared for marketing two years ago because its manufacturer showed that it was substantially equivalent to yet another device cleared in 2003, and so on, all the way back to a device that was being marketed when the law was enacted in 1976,” wrote Dr. Challoner in a recent Perspective for the New England Journal of Medicine. “But that original device might never have been assessed for safety and effectiveness, nor perhaps any subsequent ones in the family tree.”²

The definition of what constitutes a predicate device can be very broad. For example, the metal-on-metal hip prosthesis marketed by DePuy as the ASR XL Acetabular System was authorized because it was deemed to be substantially equivalent to other approved predicate devices. This was despite the fact that the ASR system used two metal parts instead of the plastic-on-metal of most previous devices.

Different Regulatory Systems

The regulatory environment for medical devices is substantially different from approval of pharmaceuticals. Perhaps the biggest difference is the use of the predicate device. The equivalent in drug approval would be requiring the first-in-class to go through the New Drug Approval process, while allowing the follow-on, or “me too” drugs, to be marketed by just pointing out their similarities.

The FDA has stated, and no less an authority than the U.S. Supreme Court has agreed, that a finding of substantial equivalence is not a determination of safety and efficacy. Again, this is a much less stringent requirement than seen in pharmaceutical regulation.³

IOM Reports on Process

Because of this and other concerns, the FDA in 2009 asked the Institute of Medicine (IOM) to review the 510(k) approval process. The IOM’s Committee on Public Health Effectiveness of the FDA 510(k) Clearance Process was tasked to look at whether the current system protected patients while still allowing for innovation and improvement of devices. If not, they were asked to formulate suggestions for policy, legislative, and other changes that might help bring that about.

In 2011, the committee published its findings. Among them:

• The FDA should design a new program that replaces substantial equivalence with a pre- and postmarket surveillance system to follow safety issues throughout the device’s life cycle;
• The FDA should develop a strategy to collect, analyze, and then act on postmarket performance;
• The FDA should review current processes to identify limits on postmarket authority and determine how to address these limits; and
• The FDA should look into the viability of a modified de novo process to evaluate the safety and effectiveness of Class II devices.

“We are hoping to make the public aware of the current defective rationale that just because a new device is similar to something else it should be marketed,” says Dr. Challoner, who was also chair of the IOM committee. “We can’t have the kinds of premarket trials that the drug companies undergo, but if we have sensitive, rapid, and transparent postmarket surveillance attached to these devices, we can know much earlier on if there is a problem.”

Aftermarket Studies

The current environment may be especially conducive to making this kind of aftermarket study possible. Large healthcare systems are evolving that can track the devices going into individual patients, and many healthcare systems already do. As electronic medical records are rolled out nationally, this will be easier to accomplish.

“With these resources, we can very quickly sift through large populations and get information on where there might be a problem,” says Dr. Challoner. “Opportunities for feedback from the clinical environment to the manufactures and the FDA are there. So far, the manufacturers have not been enthusiastic.”

There is evidence from other parts of the world that large-scale registries can prove useful. Indeed, the first indications of problems with the metal-on-metal hip replacement came from overseas.

“The Scandinavian countries and Australia both have registries,” says Dr. Kraay. “They get good numbers of patients and have good follow-up reporting. Inferior devices have definitely shown up earlier than if this type of surveillance was not performed.”

What’s Next?

The release of the committee’s report was met with differing opinions. Some representatives of the medical device industry were not in favor of the suggestions, while some patient advocacy groups said the findings did not go far enough.

Multiple requests to the FDA for input on this article were not acknowledged. However, a news release sent out after the IOM report was released included a quote from Jeffrey Shuren, MD, director of the FDA’s Center for Devices and Radiological Health, saying that the FDA “believes that the 510(k) process should not be eliminated but we are open to additional proposals and approaches for continued improvement of our device review programs.”⁴

There is agreement among the experts interviewed that medical devices are not likely to be regulated to the level of pharmaceuticals. The economics of the industry would not support full-scale trials because engineers or physicians in their garages put many of the devices together. They also point to the impossible nature of doing many randomized, blinded, placebo-controlled trials, especially where surgery or another invasive procedures are required.

In addition, much of the innovation has been incremental in nature. Most of the newer devices are improvements on older versions. So, it is a fair question to ask if there is a need for a very rigorous approval processes. “For instance, consider total hip replacements,” says Dr. MacKenzie. “The original system by Charnley was really the major innovative leap. One wonders how much more slowly this remarkable therapy would have presented in a more highly regulated environment.”

FDA Balancing Act

Going forward, the FDA has a balancing act that they have to perform. On one hand is the demand from the public (and some rumblings from Congress) that medical devices be safe and effective. On the other is the need to not unnecessarily stifle creativity.

“The FDA finds itself in the middle,” says Dr. Mac­Kenzie. “We, as a society, want to be sure systems exist to protect the patients. Yet, we also want assurances that the evolution of technology is not inhibited to the point it thwarts innovation and stops the public from enjoying its benefits.”

He says the FDA is hunting for the proper equilibrium where devices not ready for human use are put on the market—but that you also don’t put up barriers to the good things, either. “If anything comes out of the IOM report, other than raising the problems of the clearance process to the attention of the public, it is the recommendation that postmarket surveillance is the key to managing the public health question of safety and efficacy,” says Dr. Challoner.

Still Confident Overall

All three physicians are unanimous in saying that, for the most part, medical devices can be recommended by rheumatologists with confidence.

“The committee said that we don’t think that there is a public health emergency,” says Dr. Challoner. “This is mainly because the noise level coming back from the patient and practitioner, except for isolated incidents, doesn’t indicate one.” He does stress that there is still a nagging concern that “the 510(k) Emperor has no safety and efficacy clothes.” In the long run, he doesn’t think this can be good for public health and might lead to low-incidence but high-impact complications.

Dr. Kraay agrees in principle but does have an added caveat: It may not always be necessary, or even advisable, to go with newest alternative. “Devices in use for a reasonable period of time and that have a good track record for performance are frequently safer than the latest alternative released to the marketplace,” he says. “Both patients and users need to understand that new is not always better.”

Dr. MacKenzie sums it up this way: “I don’t think that the recent problems with medical devices that have risen recently in respect to medical devices assault the fundamental and well-established value of the treatments in general. Very thoughtful people on all sides of the issue are now giving it careful consideration, and I take comfort in that.”

Kurt Ullman is a freelance journalist based in Indiana.

References

1. Porucznik MA, Kennedy J. The 510(k) pathway: Changes may be coming. AAOS Now. www.aaos.org/news/aaosnow/dec09/reimbursement2.asp. Published December 2009. Accessed October 18, 2011.
2. Challoner DR, Vodra WW. Medical devices and health—creating a new regulatory framework for moderate-risk devices. N Engl J Med. 2011;365:977-979.
3. Medtronic, Inc. v. Lohr, 518 US. 470.
4. U.S. Food and Drug Administration. FDA to seek public comment on IOM recommendations. www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm265908.htm. Published July 29, 2011. Accessed October 18, 2011.