An estimated 500,00 metal on metal hip replacement implants have been installed in American patients, and the United States Food and Drug Administration begins meeting this week to determine why a disproportionate number of these implants are failing earlier than expected. This investigation is a response to several years of patients complaining of swelling and other pain associated with the metal hip implants, which in some cases requires patients to undergo a second hip replacement surgery. Though original product tests performed on the metal on metal implants suggested they would be more durable than their ceramic or plastic counterparts, recent tests conducted by British medical professionals indicates that metal hip implants have to be replaced with greater frequency. Hip replacement implants last an average of 10 to 15 years, according to current medical research, but medical experts working on behalf of the world’s largest artificial joint registry have recommended that surgeons stop implanting metal-on-metal hip replacements, pointing to data revealing that about six percent of all metal on metal implants must be replaced within their first five years, as compared to the two percent of ceramic or plastic implants that need to be replaced within the same time period. These same medical experts recommend that patients with metal on metal hip implants undergo an annual blood test to ensure that no dangerous metals are entering the blood stream as a result of artificial joint friction. Currently, the United States Food and Drug Administration has made no similar recommendations regarding metal on metal hip implants, which initially entered the market with the fast-tracked approval of the FDA.