The controversy over metal-on-metal hip implants has ensnared 21 companies that have been required by the U.S. Food and Drug Administration to do post-market studies into whether their implants shed high levels of metal debris into patients’ bloodstreams.
But orthopedic surgeons have played a role in the metal-on-metal controversy, too, according to a report from patient safety group the ECRI Institute.
Part of the implants’ failure rate can be blamed on doctors who used them in the wrong types of patients, said a physician quoted in the report, Dr. Javad Parvizi, a professor of orthopedic surgery with Thomas Jefferson University Hospital in Philadelphia.
“Metal-on-metal did have promise for a very small population,” Parvizi said. “For extremely heavy males who were very active, it was a great option compared to all of the other bearing surface options.”
The problem is doctors prescribed metal-on-metal implants to a much wider population than they should have, figuring their bigger femoral head diameter was more likely to reduce the likelihood of postoperative dislocation, according to Parvizi.
“Surgeons utilized them much more commonly and because of that we are paying a price,” he said.
Researchers know that metal-on-metal bearing surfaces generate metal particles in the blood, but what they don’t know is exactly what effect that has on patients, according to Parvizi. “Metal-on-metal technology for the most part would be very difficult to bring back,” he said.
Another orthopedic surgeon — Dr. Michael Berend, of Franciscan St. Francis Health’s Center for Hip & Knee Surgery in Mooresville, Indiana — cautioned against lumping all metal-on-metal hip implants together.
His medical practice has implanted more than 1,200 patients with Biomet’s M2a Magnum metal-on-metal hip implants and has had “an excellent early track record.”
“There are significant differences in manufacturing, in tolerances, in design … in the components, and in the way they’re implanted,” he said. “Not all metal-on-metal implants are created equal.”
[Photo from nih.gov]
My email address is [email protected] I am compiling a list of the 21 companies who manufacture/market metal on metal hips. If you know the names of any of these companies please email them to the address above. So far I have Depuy, Zimmer, Biomet, and Pinnacle. Thanks for your help!!!
I received a Depuy ASR XL Acetabular hip and had to go through revision surgery just 4 years later. I am doing extensive research on MOM hips and am trying to put together a list of all the companies who manufacture and market these devices. I have read in several articles about the FDA mandate to the 21 companies who manufacture MOM hips but I can't find a list of who these companies are. Any help would be greatly appreciated. Thank you.
Dr. Berend is correct. Variation in product designs, tolerances, material processing and manufacturing as well as implantation methods can significantly impact product durability and performance over time. It may be unrealistic to expect a manufacturer to physically test their products for every possible combination of design, tolerance, material, etc due to cost and time limitations. An alternative is to use virtual testing and simulation to predict product performance under varying conditions. One company providing these virtual simulations today across multiple industries is VEXTEC – check it out at www.vextec.com.
Here's a link to ECRI Institute's Emerging Technology Brief enewsletter featuring our article on metal on metal hips: https://www.ecri.org/Documents/Esource/ETB/Emerging_Tech_Brief_March_2012.pdf.
Katie- I was unable to find the report on ECRI's site. I saw the report in ECRI's "emerging technology brief" free monthly email. You could join that list on their site.
The sales agents of the manufacturers had something to do with the overuse of these devices, and these people were in turn trained and compensated by the manufacturers. Also, as was noted in the article, all metal-on-metal systems are not not identical, and the strategic emphasis on quality systems also differs among manufacturers. This is a complicated situation, and pinning the blame on this mess onto the 510(k) premarket clearance system (e.g. Consumers Union) does not help avoid problems such as these.