The United Kingdom’s health regulator is recommending that patients who have received hip replacement systems made from all-metal parts be monitored once a year for as long as they have the implant. The news comes just after the British Medical Journal (BMJ) and the British Broadcasting Company (BBC) announced the results of a joint investigation into problems with the medical devices.
Traditional hip implants are made with ceramic or plastic parts, but newer hip devices have employed an all-metal design built to hold up better over time. However, they appear to to be less durable than traditional implants. The flaw is in the all-metal design. As the metal ball rubs against the metal socket, bits of metal debris may fall into the joint space, causing the tissue to swell and become irritated. Not only can this condition cause pain for the patient, it can hasten the failure of the device, causing loosening, fracturing or dislocation. Revision surgery is often required to remove and replace the failed device.
But the metal debris has been linked to the possibility of even more complications if the bits of metal seep into the bloodstream. Patients have tested positive for chromium and cobalt, and have reported symptoms such as pain and fatigue. Some medical experts say that this type of blood poisoning can put patients at greater risk for developing conditions such as cancer.
One metal-on-metal type of hip replacement has already been recalled worldwide – DePuy Orthopaedics’ ASR XL Acetabulator hip replacement and hip resurfacing systems. About 93,000 people are affected by the recall. The FDA has also received complaints on other all-metal hip implants. The devices and their reported failures triggered an investigation into all metal-on-metal hip implant manufacturers by the United States Food and Drug Administration (FDA). The agency is currently reviewing complications associated with the devices but has yet to issue a recommendation such as that by the British agency.