Federal health regulators confirmed yesterday that problems from metal-on-metal hip replacements may result soft tissue damage and other complications as metal particles are shed into the body, resulting in new guidelines for doctors and patients.
A safety communication was issued by the FDA involving the controversial implants on January 17, providing the agency’s current assessment of the risks and issues with the all-metal artificial hips.
The FDA has been investigating metal hip implants for the last few years, as more and more doctors and patients complained about the side effects of metal-on-metal hips, such as pain, loosening of the components and early failures, which may be linked to metal debris that is released into the the body as the metal parts rub against each other.
“Metal-on-metal hip implants have unique risks in addition to the general risks of all hip implants,” the FDA determined. “Metal release will cause some tiny metal particles to wear off of the device around the implant, which may cause damage to bone and/or soft tissue surrounding the implant and joint.”
New Recommendations for Doctors
The FDA now sees the metal-on-metal hip implant as a device of last resort and recommended that doctors only choose metal-on-metal hip implants if the benefit-risk profile outweighs that of using another type of hip system.
The agency’s information for orthopedic surgeons advised doctors to pay close attention to patients with metal-on-metal hip implants and to look for signs and symptoms of common problems associated with those artificial hips.
The FDA also provided doctors with a list of patient types who were considered high risk for metal hip implant complications which includes:
- Patients with bilateral implants
- Patients with resurfacing systems with small femoral heads (44mm or smaller)
- Female patients
- Patients receiving high doses of corticosteroids
- Patients with evidence of renal insufficiency
- Patients with suppressed immune systems
- Patients with suboptimal alignment of device components
- Patients with suspected metal sensitivity (e.g. cobalt, chromium, nickel)
- Patients who are severely overweight
- Patients with high levels of physical activity
Doctors should consider metal ion testing for any patients who show signs of their metal hip implant not functioning properly, the FDA warned. But the agency stated that patients without symptoms did not need to be tested and noted that at this time the FDA does not believe there is enough evidence in the U.S. to link high levels of metal ions in the blood to localized lesions or the need for revision surgery.
Metal Hip Recalls, Problems Led to Investigation
The FDA began taking a closer look at metal-on-metal hip implants after a DePuy ASR metal-on-metal hip recall in August 2010. That was followed by other recalls and numerous reports of problems from doctors and patients, many of whom claimed a condition known as metallosis, a form of metal blood poisoning.
About 93,000 of the DePuy ASR implants were sold worldwide before the manufacturer discovered that about 12% to 13% were failing within five years. The use of metal-on-metal hip replacements has fallen sharply since the recall, with most experts concluding that they provide little or no benefit over other designs.
Johnson & Johnson now faces thousands of DePuy ASR hip lawsuits in the United States, alleging that they failed to adequately research the design or warn about the risk of hip replacement problems.