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Did IOM Put the Final Nail in the Coffin of Metal-on-Metal Hip Implants?

Published: August 3, 2011Shana Leonard Source: MPMN Medtech Pulse

hip implantThe medical device industry clearly anticipated in advance that it would not support the results of the review of the 510(k) process by the Institute of Medicine (IOM), which was released last week. But few expected that the IOM would determine that the current system should be scrapped and a new process devised—perhaps least of all FDA. And while the future regulatory pathway appears to be uncertain for ‘moderate-risk’ devices, the IOM’s report does seem to confirm one thing: Metal-on-metal hip implants are in for a bumpy ride.

In the report, the IOM concludes: “When the FDA assesses the substantial equivalence of a device, it generally does not require evidence of safety or effectiveness, and when a device is found to be substantially equivalent to a predicate device, the new device is assumed to be as safe and effective as the predicate because of its similarity. Devices that were on the market before the Medical Device Amendments were never systematically assessed for safety and effectiveness—but they are being used as predicate devices. This leads the committee to find that 510(k) clearance is not a determination that the cleared device is safe or effective. The committee concludes that the 510(k) process lacks the legal basis to be a reliable premarket screen of the safety and effectiveness of moderate-risk devices and, furthermore, that it cannot be transformed into one.”

Included in this class of ‘moderate-risk’ devices whose safety and efficacy is being called into question are hip implants, notably of the increasingly controversial metal-on-metal (MoM) variety. DePuy, for example, caused a significant stir last year when it issued a voluntary recall for its ASR MoM hip implant system upon learning that a higher number of patients than expected required early revision surgery. Furthermore, MoM implants, in general, have drawn fire in recent years as studies and information increasingly criticize the implants’ release of metal ions into the bloodstream, potential to inflame surrounding tissue, and relation to additional complications.

In May, FDA took action, issuing 145 orders to 21 MoM implant manufacturers for postmarket surveillance studies. With the IOM’s recommendation to develop a new regulatory framework for these (and other) Class II devices, however, MoM implants may face some serious regulatory challenges. While a completely new system is somewhat unlikely, it is clear that change, in some form or another, is on the horizon for MoM implants and other Class II devices.

I speculated in a recent editorial that, after being tried in the court of public opinion, MoM implants’ days may be numbered as manufacturers turn to other bearing material options over time. Depending on FDA’s course of action following IOM’s recommendations, this 510(k) review process could be the death knell. What do you think about the future of MoM implants? And what do you think FDA will do in light of IOM’s drastic recommendations? Let us know in the comments section below. —Shana Leonard