In February, the U.S. Food and Drug Administration (FDA) provided information to the public advising of potential medical effects that can occur with metal-on-metal hip implants.
Makers of such metal-on-metal implants, such as Johnson & Johnson and its subsidiary DePuy Orthopeadics; Smith & Nephew, and Wright Medical have been swamped with lawsuits for injuries and negative health effects allegedly caused by the devices.
The FDA points out that metal-on-metal hip implants have the same adverse effects as any other type of hip implant such as loosening, infection, bone loss, fracture of the device or bone, and joint dislocation.
But the FDA openly warns of the additional medical effects unique only to metal-on-metal hip implants. In the report, information is provided that metal debris from the implant may cause a negative reaction around the joint that leads to deterioration of the surrounding tissue. This deterioration can cause a loosening of the implant, which will cause the device to fail.
The debris may also cause metal ions to be released into the bloodstream, which leads to a type of metal poisoning called metallosis. According to the FDA’s report, other medical problems caused by the metal ions overloaded in the body may include: general hypersensitivity reaction (skin rash), cardiomyopathy, neurological changes including sensory changes (auditory, or visual impairments), psychological status change (including depression or cognitive impairment), renal function impairment, and thyroid dysfunction (including neck discomfort, fatigue, weight gain or feeling cold).
Traditional hip implants are made of plastic or ceramic parts that can last up to 20 years. Initially, the metal-on-metal designs were recommended for patients that were younger or had higher levels of activity in their daily lives, and the manufacturers claimed that they would last longer and perform better for more active lifestyles.
But when patients implanted with the all-metal devices began complaining of pain, numbness, swelling, clicking or popping, and difficulty walking, many of them resulted in device failure. Many patients subsequently had to undergo revision surgery to replace the device, which are usually more painful than the original joint replacement surgery.
Reports indicate metal-on-metal designs are failing in as little as five years.