Nearly 75 percent of revision surgeries to remove and replace a hip replacement within five years of initial implantation occur in patients who received a metal-on-metal device, according to a Canadian study.
Researchers pored through data involving 60,000 hip replacements performed across Canada between 2003 and 2011. They found that the need for revision surgery was greater in patients who had large-diameter modular metal-on-metal implants compared to patients who had more common plastic devices.
Traditional hip replacement systems are made with ceramic or plastic parts, and can last 20 years or more before needing to be replaced. In the past few years manufacturers began offering all-metal, or metal-on-metal devices, which were designed to be more durable and last longer. They were considered ideal for younger, more active individuals. However, it was soon discovered that the devices were failing at a faster than expected rate in five or fewer years.
Surgeons discovered that the device failures were prompted in many cases by inflammation and tissue damage surrounding the joint space, caused by bits of metal debris flaking off when the metal parts of the device rubbed together. In some cases metal ions leeched into the bloodstream causing a type of blood poisoning known as metallosis. The condition has been associated with a variety of symptoms including neurological problems, fatigue and headaches. Studies have shown that metallosis can damage DNA, which may lead to serious health problems including cancer.
Tens of thousands of lawsuits have been filed against the manufacturers of metal-on-metal hip implants, including Johnson & Johnson, whose subsidiary DePuy Orthopaedics in 2010 issued a recall of its all-metal ASR hip replacement system due to high failure rates, which first brought to light the serious problems associated with metal-on-metal hip implants.
Source: Global News