On June 28, 2012 the Federal Drug Administration discussed metal-on-metal (MoM) hip systems and highlighted issues relating to local and systemic complications. Health experts concluded there is little reason for the continued use of these devices due to growing evidence that they expose patients to dangerous metallic particles.
For many decades physicians preferred orthopedic implants which are coated with plastic or ceramic. In the past ten years, a growing movement towards metal devices occurred after laboratory tests suggested these devices would experience less wear and tear. The metal-on-metal devices also were thought to dislocate less frequently.
In 2010 approximately one third of hip implant procedures utilized metal-on-metal implants with many patients unaware of the increased risks including metal toxicity. It is estimated that more than half-million U.S. patients currently have metal hip replacements.
Recent data suggests that as the metal-on-metal devices wear, they can release metallic particles which in turn cause tissue and muscle damage. British experts in March of 2012 found evidence that metal-on-metal implants are four times more likely to fail compared to plastic and ceramic models. Dr. William Rohr of Mendocino Coast Disctrict Hospital and chair of the panel notes, “I do not use metal-on-metal hips, and I can see no reason to do so.” Many doctors are now returning to the plastic and ceramic models which were once the standard of care.
FDA experts suggested that patients with pain and other symptoms who have metal-on-metal devices should get x-rays and blood tests to monitor metal levels. For those without pain, an annual x-ray is sufficient monitoring according to the panel.
In 2010, DuPuy Orthopaedics, a subsidiary of Johnson & Johnson declared a recall of the ASR hip replacement system. Many patients who had already had the defective device implanted have filed lawsuits against DePuy as they claim to not have been warned against the risks.References: Defective Medical Device litigation, Hip/Knee Replacement