The Food and Drug Administration issued cautionary guidelines for metal-on-metal (MoM) hip replacements that range from selecting the right surgical candidate to determining when to replace the hardware.
They stated all-metal implants can shed metal where the two components connect, such as the ball and the cup that slide against each other during walking or running and cause problems. The release of metal will cause wear and tear on the implant and can damage bone and soft tissue surrounding the implant.
Implant materials like plastic and metal are supposed to last 15 years before wearing out. But the all-metal hips, which companies rarely tested in patients before marketing them, are failing at high rates not long after implantation, according to the NY Times. As a result, thousands of patients have had to undergo a painful and costly operation to replace the implant.
An estimated 500,000 patients in the United States have received a metal hip implant, meanwhile, some are failing too early. The Food and Drug Administration is now proposing that the news rules could stop manufacturers from selling such implants.
To reduce this risk, the FDA has said today that surgeons should determine the patient’s individual characteristics, such as; age, sex, weight, diagnosis, and activity level all come into play, with a higher risk for increased device wear. At that time, surgeons should determine the selection of a metal-on-metal (MoM) hip replacement for their patient only after determining that the benefits of using a MoM hip implant outweigh the risks, in comparison to using alternative hip systems like, metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic or ceramic-on-metal.
The FDA warns not to use metal-on-metal implants on the following:
- Patients with known moderate to severe renal insufficiency
- Patients with known metal sensitivity (e.g. cobalt, chromium, nickel)
- Patients with suppressed immune systems
- Patients currently receiving high doses of corticosteroids
- Females of childbearing age
The new guidelines for MoM implants from the FDA also state that the makers of artificial hips with all-metal components would have to prove the devices were safe and effective before they could continue selling existing ones or obtain approval for new all-metal designs.
Johnson & Johnson is the biggest manufacturer of all-metal devices and recalled its ASR hip implant in 2010 following safety problems.
Smith & Nephew had to withdraw a component of one of its all-metal artificial hip systems last June after reporting a higher level of patient problems with the device.
Stryker Corp begun recalling some components of its MoM implants in July due to risks associated with corrosion.
Other hip implant makers include Zimmer Holdings Inc and Wright Medical Group.