FDA to Require PMAs for Metal-on-Metal Hips

Following widespread media attention over patient injuries and increased scrutiny by the FDA, manufacturers of certain types of metal-on-metal hips now will have to submit premarket approval applications to keep their devices on the market.

Under a final FDA order unveiled this month, two types of devices — hip joint metal/metal semi-constrained with a cemented acetabular component and hip joint metal/metal semi-constrained with an uncemented acetabular component — will require PMAs.

As a result, PMA applications must be filed with the agency by May 18 if manufacturers want to continue marketing their MoM total hip replacement devices and/or market new MoM total hip replacement devices.

“Given the known risks, the FDA believes that there is insufficient evidence and information to conclude that general controls in combination with special controls would provide reasonable assurance of the safety and effectiveness of these devices,” the agency says.

Manufacturers will be required to submit a PMA application that includes:

• Any risks known — or that should be reasonably known — to the applicant;
• The effectiveness of the device that is the subject of the application; and
• Full reports of all nonclinical and clinical information from investigations on the safety and effectiveness of the device for which premarket approval is sought.

In comments to the 2013 proposed order on the topic, groups provided more details about the risks associated with these devices. For example, the National Research Center for Women & Families noted what it saw as serious issues related to MoM hips, “including the lack of scientific evidence (clinical trials), the higher revision rates for women, the higher revision rates compared [with] metal on polyurethane hips, and the lack of evidence that MoM hips have benefits that outweigh their risks.”

Meanwhile, while acknowledging that these devices perform well in the majority of patients, the American Association of Orthopaedic Surgeons said in comments that more research was needed into adverse local tissue responses related to MoM bearings.

Read the final order here: www.fdanews.com/02-16-FDAHips.pdf. — Jonathon Shacat