Patients with failing metal-on-metal hip implants often complain of pain. New research shows the pain these patients are experiencing may be caused by tissue damage and not by wear of the implant.
Traditional hip implants are made of ceramic or plastic parts, but a newer generation of hip implants introduced a decade ago featured an all-metal design. These metal-on-metal implants have recently been shown to fail at a higher than expected rate. The failures appear to be accelerated by the leeching of metal ions from the devices into surrounding tissue, causing tissue damage. The ions have also been found to enter the bloodstream and cause a type of blood poisoning known as metallosis.
The new study, reported last month at the American Academy of Orthopaedic Surgeons, set out to determine the causes of unexplained pain among patients who had received metal-on-metal hip implants who were undergoing revision surgery to remove and replace their device. Researchers compared 50 patients who were undergoing revision surgery due to unexplained pain compared to 48 patients who were having surgery because of loosening, misalignment, infection or fracture of their device. Researchers found that 12 percent of patients had some buildup of metal deposits in their soft tissue, and 10 times as many patients in the unexplained pain group had high-grade tissue damage compared to the other group.
Researchers concluded that patients with unexplained pain should be followed closely by their doctors. Identifying these patients early is key to avoiding significant tissue damage caused by the faulty implants.
Source: Medical News Net