In 1976 medical devices were added to the Food, Drug and Cosmetic Act, placing metal hip implants under FDA regulation. At this time metal-on-metal hip implants were categorized under a Class III or “high risk,” category. Nonetheless, the FDA made the determination to allow regulation of hip implant devices through the 510(k) fast track approval process. Metal-on-metal hip implants were not widely used during the next twenty years, however by the late 1980’s, second-generation metal hip implant designs had been introduced.