On February 18, 2016, the FDA issued a final order requiring manufacturers to submit a premarket approval (PMA) application for two types of MoM total hip replacement devices: the hip joint metal/metal semi-constrained with a cemented acetabular component and the hip joint metal/metal semi-constrained with an uncemented acetabular component.
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 has determined that these devices should remain Class III (higher risk) devices and PMA applications must be filed with the agency by May 18, 2016 if a manufacturer wants to continue marketing their MoM total hip replacement devices and/or market new MoM total hip replacement devices.
Manufacturers will be required to submit a PMA application that includes: (1) any risks known, or that should be reasonably known, to the applicant; (2) the effectiveness of the device that is the subject of the application; and (3) full reports of all nonclinical and clinical information from investigations on the safety and effectiveness of the device for which premarket approval is sought.
Other FDA activities to date include:
- Working with the manufacturers of MoM hip implants to evaluate the devices in a Magnetic Resonance Imaging (MRI) environment and to develop device specific labeling for MR Conditions, which would help ensure safe scanning of patients with MoM hip implants.
- Supporting the development of technologies to improve image quality around metal implants; this is important because the metal in the devices can prevent doctors from monitoring bone and soft tissue around the implant for signs of problems.
- Encouraging metal ion test labs to participate in a trace element proficiency testing program (e.g., New York State Department of Health, Wadsworth Center) to ensure consistency and reliability in metal ion test results.
- Continuing to review published medical literature, Medical Device Reports (adverse event reports) submitted to the FDA, post-approval study reports and data from several orthopaedic device registries from within and outside the U.S. to better understand possible adverse events associated with metal debris from MoM hip implants.
- Launching the International Consortium of Orthopaedic Registries (ICOR), an international collaborative effort that aims to address differences in orthopaedic registries around the world and allow for collaboration to harmonize and utilize the data available from these registries.
- Requesting and reviewing device retrieval analyses from the manufacturers of the hip systems distributed in the U.S. This will help us understand how and why certain MoM implants fail over time.
- Pursuing collaborations with multiple partners, domestically and internationally, to fully understand the postmarket performance of MoM hip implants and to document the occurrence of and signs and symptoms associated with specific adverse events.
- Issued a Safety Communication to provide updated safety information and recommendations to patients and health care providers.
- Issued a proposed order requiring manufacturers of MoM total hip replacement systems to submit premarket approval (PMA) applications.
- Convened the Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee to seek expert scientific and clinical opinion on the benefits and risks of MoM hip implants. Panel members discussed:
- Failure rates and modes;
- Metal ion testing;
- Imaging methods;
- Local and systemic complications;
- Patient risk factors;
- Labeling considerations; and
- Considerations for follow-up after surgery.
- Instructed manufacturers of MoM total hip replacement systems to conduct a postmarket surveillance study of these devices.
- Five manufacturers currently market MoM total hip implants in the U.S. and all five have approved postmarket surveillance study plans.
- Data from these studies will provide patients and health care providers with additional information about the safety profiles of the implants, including the effect of metal ion concentrations in the bloodstream.