Metal-on-Metal Hip Implant Raises Concerns. The authors of a newly-published study say the makers of metal-on-metal hip implants have no basis for their claims that these devices offer any advantages over traditional metal-on-polyethylene or ceramic-on-polyethylene hip implants. According to the study, which is published in the British Medical Journal, people with all metal hip implants are doubly at risk of requiring a repeat procedure.
All-metal hip implants have been under scrutiny for some time. In May, the U.S. Food & Drug Administration (FDA) asked DePuy Orthopaedics and 20 other manufacturers of metal-on-metal hip implants to conduct safety studies aimed at determining how often they fail prematurely, and if these devices are shedding dangerous amounts of metallic debris in patients. It is believed excess shedding of metal debris can lead to tissue damage, premature device failure, the need for revision surgery, and even long-term health problems.
Worldwide recall of DePuy’s ASR hip implant
The FDA order followed the August 2010 worldwide recall of DePuy’s ASR hip implant, an all-metal hip implant. The DePuy ASR hip implant recall followed complaints that the devices failed years earlier than expected in many patients.
And in September, a British hip replacement registry found more widespread evidence of early failure for the metal-on-metal devices.
This new study, which was sponsored by the FDA, looked at 18 studies including more than 3,000 patients as well as outcomes from 830,000 hip replacement surgeries reported to various national registries.
Data from the three largest registries – from Australia, New Zealand, and England and Wales – revealed evidence of higher rates of early implant failure associated with metal-on-metal devices, compared to metal-on-polyethylene implants. The study found no evidence that newer hip replacements, including all-metal hip implants, offered any advantage over those made with traditional materials.
“A large and high-quality randomized controlled trial of bearing surfaces in total hip replacement needs to be conducted before any claims of benefit are made,” the journal article stated.