In Europe these concerns have led to calls to ban metal-on-metal hip replacement devices. Writing in March in the journal The Lancet, British researchers concluded that "metal-on-metal stemmed articulations give poor implant survival compared with other options and should not be implanted." Metal-on-metal implants had a five-year failure rate of more than 6 percent, three times higher that seen with ceramic or plastic joints.
Mindy Tinsley is a spokeswoman for metal implant maker DePuy Orthopaedics Inc., which is owned by Johnson & Johnson. She said that "DePuy believes that no single bearing surface meets the needs of all patients, and metal-on-metal implants provide the potential benefit of greater function and a lower risk of dislocation for some patients."
Tinsley also said that all metal-on-metal implants are not alike and they should not be grouped together if problems arise.
One orthopedic expert agreed. Dr. Joshua Jacobs, first vice president of the American Academy of Orthopaedic Surgeons, said that "metal-on-metal devices are not all the same. You have to go down to the individual product to fully understand the result. When you lump metal-on-metal together you miss a lot of important differences."
According to Jacobs, who is chairman of the department of orthopaedic surgery at Rush University Medical Center in Chicago, the advantages of metal-on-metal implants are that there is typically less wear on the joint, leading to less loosening and less bone loss over time.
In addition, he said, metal allows for a thinner, larger socket and head, which makes it less likely the hip will dislocate after surgery, which is a common failure of other types of hip replacement.
Still, given the problems with these devices, Jacobs agrees that patients need to be monitored.
"We are trying to learn the optimal way of monitoring patients with metal-on-metal implant
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