Canadian Study Outlines Metal-on-Metal Hip Trends The Canadian Institute for Health Information h

Canadian Study Outlines Metal-on-Metal Hip Trends
The Canadian Institute for Health Information has published new data that suggests people who have metal-on-metal hip implants are more likely than those with the metal-on-plastic type to need a replacement within five years. However, the rate of revisions is still low. The report was based on nearly 60,000 hip replacements done across Canada between 2003 and 2011. Data from Quebec were not included.

People with large-diameter modular, metal-on-metal implants had a 5.9 percent chance of needing to have the implant replaced within five years, compared to a rate of 2.7 per cent among people who received the more common metal-on-plastic implant. Nearly three out of every four replacements logged into the Canadian joint replacement registry were metal-on-plastic units.

Metal-on-metal hip replacements have faced intense criticism and scrutiny in recent years, particularly products such as DePuy Orthopaedics’ ASL hips, which were accused of depositing metal fragments into patients’ bloodstreams and surrounding soft tissue. These units were recalled from the market because of the publicity the negative events garnered. Johnson & Johnson, which owns DePuy Orthoopedics, is facing thousands of lawsuits in regards to the metal-on-metal hips.

According to The Star Phoenix, a Canadian newspaper, the number of negative events related to the all-metal hips did not necessarily demand a recall.

Canadian orthopedic surgeons took a more conservative approach to the metal-on-metal implants and it turned out to be the way to go, Michael Dunbar, M.D., an orthopedic surgeon from Halifax and co-chair of the joint replacement registry, told the paper.

“It was the right side of the street to be on, for sure,” Dunbar said. “It was the fact of the matter that in the United States in the late 2000s almost 45 per cent of every male in the country (who got a hip replacement) got metal-on-metal. So this is why it’s such a big issue in the United States.”

Dunbar said the differences between the United States and Canadian situations underscore why it’s important to gather information on joint replacements. Currently the joint replacement registry is a voluntary one, and captures only a portion of the procedures done in the country.

British Columbia and Ontario are moving to make it mandatory for these procedures to be recorded in the registry, but Dunbar wishes others would follow suit.

“We have a voluntary system and until recently we’ve been down around 50 percent,” he said. “We think that all implants should be registered because this is important. We’re spending the nation’s treasure on this stuff. This is a top healthcare priority in Canada. We want to make sure we can deliver the very best product to the patients in our country. And we want to make sure that the money that we’re spending … is best spent for the most appropriate implant for the most appropriate patient.”