Health Canada Says Metal-on-Metal Hip Replacement Patients Need MonitoringMay 10, 2012 | Parker Waichman LLP
Health Canada is now the latest medical products regulator to issue a warning regarding the dangers of metal-on-metal hip replacement devices. The agency issued new guidance yesterday, advising doctors to follow-up with metal-on-metal hip implants for at least five years after surgery.
Metal-on-metal hip implants first began raising safety concerns after the August 2010 recall of DePuy Orthopaedics' ASR hip implant devices. A growing number of reports worldwide have since linked metal-on-metal hip replacements with loosening, and significant soft tissue reactions thought to be the result of increased levels cobalt and chromium ions shed by metal-on-metal hip implants.
In May of last year, the U.S. Food & Drug Administration (FDA) asked 21 makers of metal-on-metal hip implants to conduct safety studies of their devices. In June, the agency will convene a panel of outside advisers to discuss the problems related to metal-on-metal hip replacements.
In February, the U.K's MHRA advised that patients fitted with large metal hip implants for total hip replacement – those with bearings of 36 mm or above – should undergo annual blood tests to check cobalt and chromium, as well as MRIs for any patient who does exhibit high metal ion levels.
Among other things, Health Canada says metal-on-metal hip implant patients should be on guard for any symptom that could point to a failing all-metal hip implant, including:
• Pain in the groin, hip or leg
• Swelling at or near the hip joint
• Onset of a limp or change in walking ability
• Limited range of motion
Patients who experience these symptoms more than 3-months post-op should undergo MRIs and other imaging tests, and possibly whole blood or serum tests for cobalt and chromium metal ion levels. Patients at higher risk for metal-on-metal hip replacement failure include women, physically active patients, patients who are severely overweight, or those with implants in both hips.
According to Health Canada, about 10% percent of the total hip replacements performed in Canada have metal-on-metal hip replacement devices.