People who have received any metal-on-metal type of hip implant should be monitored every year for the rest of their lives in order to rule out possible complications, the United Kingdom’s Medicine and Healthcare products Regulatory Agency (MHRA) announced this week. The news comes on the heels of a report by the British Medical Journal (BMJ) and the British Broadcasting Company (BBC) that found problems with the all-metal artificial hips may have been known for years but nothing has been done to ban their use.
Hip replacement systems were traditionally made of plastic or ceramic parts, but newer models feature an all-metal design, which includes a metal ball that turns within a metal socket. The newer devices were made to be more durable, but data soon showed that the devices were actually failing at a higher than expected rate in just a matter of years. Not only did these failed devices require patients to undergo revision surgery to replace their defective implants, but they were also causing another problem.
Doctors discovered that as the metal parts of the implant rubbed against each other, tiny bits of metal debris could fall into the joint space, possibly causing inflammation and pain. This problem allows metals such as cobalt and chromium to leech into the bloodstream and cause a type of blood poisoning known as metallosis. This condition can cause pain and fatigue, and may put sufferers at greater risk for developing cancer.
Symptoms of metallosis may take years to emerge. Thus, MHRA is recommending that patients with these devices be monitored each year for as long as they have the metal-on-metal hip implants.
The U.S. Food and Drug Administration (FDA) has yet to make such a recommendation on whether the implants should be banned from the market; however, the agency recently announced that it is working with several all-metal hip implant manufacturers and will be reviewing complaints associated with all metal-on-metal artificial hips.