On September 30, 2011, the New York Times published an article referencing the increase in the number of patients having defective metal-on-metal hip implants explanted and replaced. The rise in the number of revision surgeries for these types of implants points to an emergent public health concern across the country. This problem is further complicated when the patient needs a second opinion to obtain a definitive diagnosis. A delay in the diagnosis and treatment of a metal-on-metal hip implant failure may increase the patient’s chance of developing permanent metal-related damage to the body.
The wear of metal-on-metal hips generating metal debris in the bloodstream presents a distinct concern to patients. The article noted that “…the particles released by some all-metal hips pose a special threat because scavenger cells dispatched by the body to neutralize the debris convert it into biologically active metallic ions. In some patients, a chain reaction begins that can destroy tissue and muscle.” The destruction of tissue and muscles can often occur without eliciting symptoms, such as pain. Of great concern, “tissue damage is also occurring in some patients with low or normal metal blood levels and in some patients who are free of symptoms.”
The evidence against metal-on-metal hips is growing. According to a recent study from England, the failure rate of metal-on-metal hips is three times the failure rate of metal-on-plastic implants. Additionally, the Food and Drug Administration (FDA) received over 5,000 reports claiming problems with metal-on-metal hips during the first six months of 2011. In May 2011, the FDA required manufacturers of metal-on-metal hip implants to conduct post-marketing studies to determine the failure rate for these types of devices, and specifically the consequences of failures for patients. Unfortunately, the results of these studies will not be available for a few years. Doctors and patients must now find ways to deal with the growing concern presented by metal-on-metal hips.
See the full New York Times article at:
http://www.nytimes.com/2011/10/01/health/01hip.html
National Joint Registry, 8th Annual Report 2011:
http://www.njrcentre.org.uk/NjrCentre/Portals/0/Documents/NJR%208th%20Annual%20Report%202011.pdf
