Metal-on-Metal Hip Implants May Pose Risk of "Systemic Toxicity"Jan 30, 2012 | Parker Waichman LLP
Fears are rising in Britain that all-metal hip implants, including DePuy Orthopaedic's recalled ASR Hip Replacement devices, could be causing more harm to patients than previously thought. According to a report from the Sunday Telegraph, advisors to the Medicines and Healthcare products Regulatory Agency (MHRA) are growing increasingly concerned that microscopic metal particles shed by the devices could cause "systemic toxicity” in the body.
For now, the MHRA continues to advise that people fitted with metal-on-metal hip implants should undergo annual check-ups for five years following surgery. It also said that those experiencing pain should be given tests to check the levels of cobalt and chromium in their blood, and an MRI or ultrasound scan to check for soft tissue reactions. That advice was issued in 2010, amid concerns that shedding of toxic metal shards could make their way into the blood stream, and cause inflammation that destroys tissue and bone.
According to the Sunday Telegraph, advisors to the MHRA are now concerned the metal shedding could slowly poison nervous system, heart and lungs. There are also concerns that increased cobalt and chromium levels in the blood could be toxic to kidneys and, in the case of pregnant women, be passed on to the unborn child.
There are also concerns that the recalled DePuy ASR hip implants might be failing at a much higher rate than thought, the Sunday Telegraph said. In August 2010, DePuy Orthopaedics, a division of Johnson & Johnson, issued a worldwide recall of its ASR Hip Resurfacing System and the DePuy ASR Acetabular System, after data from the National Joint Registry of England and Wales showed that 1 out of every 8 patients (12%-13%) who had received the devices had to undergo revision surgery within five years of receiving it. But a new study conducted in Britain found up to a 50 percent failure rate at six years for those who received a DePuy ASR hip implant in a total hip replacement procedure. Among those implanted with the more limited resurfacing treatment, one in four products failed within the same period, according to the study.