Health Canada Issues Warning on Hip and Knee Replacement Failure

Toronto, CanadaHealth Canada has joined other agencies and experts in warning about the risks associated with hip and knee replacement implant failure. Specifically, the health agency warned about the risks associated with metal-on-metal hip implants. Complaints about hip implant failures have resulted in hip replacement lawsuits, alleging the metal-on-metal hip replacement devices were defective and have a higher rate of failure than traditional hip replacement devices.

According to Health Canada (4/11/12), patients should be aware of pain in the groin, hip or knee; swelling at or near the hip joint; pain or a change in mobility, or limited range of motion. The agency warned that patients who were at an increased risk of hip replacement failure are female patients, patients who have high activity levels, patients who are severely overweight and patients who received implants in both hips.

Health Canada's hip implant warning suggests that the increased risk of failure is linked to metal ions that are released into the patient's bloodstream because of wear and tear when the metal components of the implant rub together.

"In recent years, there has been an increase in awareness of pain, implant loosening and significant soft tissue reactions thought to be the result of increased levels of metal (cobalt and chromium) ions in the surrounding joint tissue," the agency warned. "Soft tissue reactions can range from fluid collection to more extensive necrotic and "psudotumor" reactions and can necessitate device revision."

The FDA is already watching metal-on-metal implants, convening an expert advisory panel in June to evaluate the risks and benefits of the hip implants. The Morning Call (5/10/12) reports on patient Steve Lorenz, who has two recalled hip implants and is hoping to convince the FDA to strengthen its rules on hip implants, which were approved without clinical trials. Lorenz reportedly received the first implant—a DePuy ASR XL—when he was 48 years old. The DePuy ASR XL has since been recalled because of high failure rates.

Patients whose hip implants have failed may have to undergo revision surgery, but revision is more complicated than the initial replacement surgery, with longer recovery times and a higher risk of complications. Doctors say that patients who have not shown symptoms of hip failure should not have the revision surgery.