Canadian patients and doctors are voicing more concerns about metal-on-metal hip replacements, as health regulators around the world continue to investigate the safety of the devices. According to a report from the CBC, four companies have recently either recalled or suspended sales of metal-on-metal hip replacement devices, while a number of research studies have raised concern that all-metal hips are more than three times more likely to fail, and can cause tissue damage around the joint.
Dr. Nizar Mahomed, the head of orthopedic surgery at Toronto Western Hospital, told the CBC that the number of Canadians with complications related to metal-on-metal hip implants is likely to rise in the coming years.
“We are just starting to see the increased numbers of revisions or failures in the metal to metal prosthesis,” he said. “I hope that it stabilizes, but there are still concerns that the number of failures will continue to increase with time.”
As we’ve reported previously, metal-on-metal total hip replacements were introduced for their purported advantages over conventional devices, such as low rates of wear and increased stability. However, concerns about all-metal hip implants started to mount in 2010, when DePuy Orthopaedics issued a recall of its ASR hip devices, after it was found that they were failing in about 12 percent of patients within just five years of implantation.
Most recently, Smith & Nephew recalled a metal cup that’s used with its R3 Acetabular System hip implant. As many as 1.6 percent of patients with the metal cup have been forced to endure a revision surgery within a year of receiving it. Most common among the complications that lead to these surgeries are infections, fractures, and dislocations of the joint, the company said.
The U.S. Food & Drug Administration (FDA) began studying all-metal hip implants shortly after the DePuy ASR hip implant recall to determine if the devices are shedding dangerous levels of metal ions into patients’ surrounding tissue and blood streams. An FDA advisory panel is scheduled to take up metal-on-metal hip implants during a two-day meeting scheduled for June 27th and 28th.
This past spring, Health Canada, the FDA’s counterpart in that country, issued a safety advisory saying that metal-on-metal implants can cause pain, “soft tissue reactions,” and that the implants can become loose. Patients with the device who are experiencing pain were advised to have an MRI, and those that show tissue damage should have the hip replacements removed and replaced.
Thousands of patients in Canada have had a metal-on-metal hip replacement since they were introduced in the mid-2000s. According to the CBC, about one in 100 patients will experience inflammation and pain. Canadian research also found that a smaller number develop pseudotumors, which will cause serious muscle and tissue damage.
Frank Cristo, who underwent the procedure five years ago, told the CBC that his pain only worsened after the surgery, so he had the implant removed and is waiting to have it replaced with a metal-and-plastic devices.
“I was told metal-on-metal was supposed to be the best,” he said. “I was good for the first month or so then I started feeling pain all the time.”