People who have received metal-on-metal hip replacement systems should be checked by a doctor every year for as long as they have the implant to ensure the implant isn’t failing or poisoning their blood, says the UK regulator of medical devices.
Metal-on-metal hip implants were introduced a decade ago as a more durable artificial hip. Traditional hip implants are made with plastic or ceramic parts, but several manufacturers began offering all-metal versions. The design turned out to be a major flaw. Most hip implants can last 20 years or more, but the newer metal-on-metal devices were beginning to fail at a higher than expected rate.
But what was causing these failures took everyone by surprise. As the metal parts of the devices rubbed together, bits of metal debris can flake off, damaging tissue in the joint space. This may lead to inflammation, which helps accelerate loosening, fracturing or dislocating of the device.
When devices fail, patients experience pain and disability. They also have to undergo revision surgery to remove and replace their devices, a process that is both more invasive and requires longer recovery than the original surgery.
The metal that falls into the joint space has also been found to seep into the bloodstream of some patients. These levels of chromium and cobalt in the bloodstream can lead to a blood poisoning known as metallosis. Patients with the condition have reported fatigue and headaches, but the long-term risks are anyone’s guess. New research suggests that these metals in the blood can damage DNA, which can lead to serious health problems including cancer.
Hundreds of thousands of people around the world have received all-metal hips from various manufacturers. Patients who have received these devices should be checked regularly for problems and have their blood tested for metals so that any problems that arise can be tended to promptly.
Meanwhile, several lawsuits have been filed against the manufacturers of these all-metal devices by people who have received the defective devices and suffered pain and injury.