FDA Study Into Hip Implant Failure Proposed

Hip implants have been in the news a lot lately, with DePuy, Stryker, Wright Conserve, Biomet, Zimmer, and Smith and Nephew all facing claims that implants – specifically metal-in-metal hip replacements – are defective and could corrode, leading to serious injury. With widespread consumer complaints and thousands of lawsuits filed, the FDA recently moved to better regulate the market and to close a loophole in the 1976 Medical Device Amendment Act by requiring all metal-on-metal hip implant makers to submit premarket approval applications. This may not have been enough, however; the FDA is still concerned with the devices’ safety, and recently announced that a new investigation will be undertaken.

After so many complaints, the FDA is finally taking solid action.

In a notice of solicitation posted on the Federal Business Opportunities website, the FDA acknowledged that there remains widespread concern about wear and corrosion of hip replacements, adding that this wasn’t a “new phenomenon” but that design changes had brought the issue to the fore once more. With this in mind, the notice announced a new project aiming to "investigate the potential link between volumetric wear and corrosion of conical head/stem taper junctions in explanted total hip replacements and clinical outcomes."

After so many complaints, the FDA is finally taking solid action to determine just how effective – or dangerous – metal-on-metal implants can be.

The notice requested private sector applications to help design and run the proposed study. The results of any eventual study, which looks likely to focus on the more modern metal-on-metal bearings and modular designs, will be used to generate a peer-reviewed journal explaining the correlation between wear and corrosion and a number of different factors (time, materials used, etc). It’s thought that the study will take about two years and will examine around 250 explanted hip replacements from different genders and in different sizes. The American Society for Testing and Materials protocol for corrosion testing will be used to analyze results.

Meanwhile, lawsuits continue against the manufacturers of implants, several of whom have voluntarily recalled their devices. The FDA study is a long time coming but may once and for all produce clear data on the effects of metal-on-metal implants.