In preparation for an orthopaedic advisory panel meeting that will be held on June 27 and 28, 2012, the U.S. Food and Drug Administration (FDA) recently released a document detailing the number of metal-on-metal hip implant adverse event reports submitted to the agency in the past ten years. According to the FDA’s document, titled “Summary of Medical Device Adverse Event Reports”, a total of 16,818 medical device reports (MDR) regarding metal-on-metal total hip replacements (THR) were submitted to the agency between the years 1992-2011. These reports were submitted to the agency’s official medical device reporting system known as the MAUDE database (Manufacturer and User Facility Device Experience).
The adverse event reports submitted to the FDA on metal-on-metal total hip replacements indicated a variety of reasons for device failure. However, the most prevalent adverse event type was the need for revision of the metal-on-metal hip device. Of the 16,818 adverse event reports the agency received regarding metal-on-metal total hip replacements, 14,131 of these reports indicated revision as the adverse event that occurred. The next most prevalent adverse event type was pain, which was the reason for 8,704 of the reports submitted. Another common adverse event noted was metallosis, the reason for 3,314 of the reports received by the FDA.
The FDA document indicates that the number of adverse event reports regarding metal-on-metal hip implants has increased substantially in only the past few years. In 2010, the agency received 2,825 adverse event reports regarding metal-on-metal hip implants. However, in 2011 the number increased significantly: the agency received 12,137 adverse event reports regarding metal-on-metal hip implants.
Medical device adverse event reports may be submitted to the FDA by a variety of entities, including manufacturers, individuals, or facilities. Although these reports may offer a useful means of assessing medical device problems in the real world, the FDA document reiterates that these reports can be flawed. Limitations posed by the MAUDE reporting system include under-reporting and bias, to name a few.
Due to the aforementioned problem of under-reporting, the number of adverse event reports regarding metal-on-metal hip implants may not be indicative of the actual number of individuals who have suffered problems as a result of the implantation of these types of devices. The number of adverse events occurring as a result of metal-on-metal hip devices may actually be higher.
See the FDA document regarding adverse event reporting of metal-on-metal hip implants at: