The US Food and Drug Administration has ordered all manufacturers of “metal-on-metal” artificial hip devices to conduct post-market studies to see whether the implants are malfunctioning or causing health problems in patients.

According to a New York Times report, the FDA’s Center for Devices and Radiological Health (CDRH) issued letters May 6 to roughly 20 manufacturers notifying them of the order. Firms will have 30 days to develop their own post-market study proposals and submit them to the regulator; manufacturers will be required to collect data from patients using their devices as well as determine the frequency of device failures. Companies targeted by the order include Johnson & Johnson’s DePuy unit, Biomet, Stryker, Wright Medical and Zimmer.

In the Times article, Dr. William Maisel, deputy director for science at the CDRH, says the action constitutes the largest order of its kind for an approved class of devices. The agency’s move follows increasing reports over the last two years of metal-on-metal hip device failures as well as health problems such as soft tissue damage due to shedding of metallic debris.