FDA is actively working in several areas to further assess the safety and effectiveness of metal-on-metal hip implants. Some activities include a comprehensive review of:
- Risk-benefit profiles
- Utilization trends
- Patient selection criteria
- Pre-operative patient counseling
- Surgical technique
- Revision rates associated with metal-on-metal hip systems in the United States
- As a part of our effort to better understand possible adverse events associated with metal debris from metal-on-metal hip systems, we continue to review published literature, Medical Device Reports (adverse event reports) submitted to the Agency, post-approval study reports and data from several orthopaedic device registries from within and outside the U.S.
- We have requested and will be 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 metal-on-metal implants fail over time.
- We are pursuing collaborations with multiple partners domestically and internationally to fully understand the postmarket performance of metal-on-metal hip systems and to document the occurrence of and signs and symptoms associated with specific adverse events.
- These efforts allow us to continue to investigate the safety and effectiveness of metal-on-metal hip implants systems and provide additional information to the public as it becomes available.
The FDA is continuing to gather and review all available information about currently marketed metal-on-metal hip systems, including information related to adverse events that may be associated with increase levels of cobalt and chromium in the bloodstream. To that end, on May 6, 2011 the FDA issued orders for postmarket surveillance studies to manufacturers of metal-on-metal hip systems. The FDA sent 145 orders to 21 manufacturers. Manufacturers will be required to submit a research protocol to the FDA that addresses specific safety issues related to these devices. Data from the studies conducted will enable the agency to better understand these devices and their safety profiles.
Metal-on-metal hip systems were marketed in the U.S. prior to 1976 legislation that gave the agency premarket authority over medical devices. As “preamendment devices,” they were automatically designated as Class III (higher risk) devices but were regulated under the 510(k) premarket notification program. The agency is currently reviewing all safety and effectiveness data related to these “preamendment devices,” including metal-on-metal hip systems, in an effort to determine their proper risk classification and how these devices should be regulated in the future. A decision on the proper classification of metal-on-metal hip systems is forthcoming but is unrelated to the postmarket surveillance order