Yesterday, the U.S. Food and Drug Administration (FDA) was slated to begin two days of hearings to learn better ways to understand and track the risks of all-metal hip replacement devices. The beleaguered all-metal hip replacement devices have been the subject of controversy over the past decade, especially the J&J Depuy ASR and Pinnacle hip replacement devices. Why, the FDA would now like to know, "were the hip devices implanted in 500,000 people without adequate testing?" according to a New York Times article of June 26, 2012.
Part of the problem is that under FDA regulations, the orthopedic implant device manufacturers were not required to perform clinical trials of hip devices prior to marketing them. The companies that manufactured hip replacement devices were also not required to follow the patients’ use, their success or lack thereof. Data on the hip replacement devices have been released to the public in some cases, and not in others. Many physicians and surgeons chose to recommend and perform hip replacement surgery because they believed the hip implant devices would improve patients’ mobility.
It appears whether the data were released to the public or not, each model of all-metal hip replacement devices has a higher failure rate than traditional implants made from combinations of materials, such as plastic and metal; and "the highest failure rate [is] associated with the DePuy ASR hip replacement device." In May 2011, the FDA ordered five manufacturers of all-metal hip replacement devices to perform studies to review whether hip implants in patients were successful or not. Thus far, FDA has approved one study plan by Biomet.
Unlike Britain or Australia, the U.S. does not have an orthopedic registry which typically follows patient results; therefore, data on failure rates is not complete. One of the most difficult problems with all-metal hip replacements is how to detect whether the metal used in the implant does damage to the patient’s body tissues and how to track such problems. Dartmouth-Hitchcock Medical Center’s Dr. Ivan M. Tomek, indicated that not much information has been forthcoming from the implant companies on this subject.
During the hearings, the FDA plans to solicit expert opinions on whether blood tests to determine the level of metallic ions in a patient’s blood and magnetic resonance imaging (MRI) tests are accurate to detect tissue damage from all-metal hip implant devices.
The long-term damage to metal-on-metal (MoM) hip devices, from chromium, cobalt, or titanium metallic ions is not yet known. Short term, the metallosis may cause symptoms that mimic infection, including pain, stiffness, redness, and swelling, and further may cause permanent soft-tissue damage in and around the hip prosthesis. Long-term, whether the metallic ions cause or contribute to cancer or other illnesses is not yet verified.
Why did this happen? Did the manufacturers not know that the MoM hips were at least potentially problematic before marketing and selling them to the world? What do their internal documents show, especially the ill-fated DePuy ASR Metal on Metal hips? It is a good example of a lack of regulation, combined with a rush to market (i.e., profits), causing many unnecessary injuries to many innocent folks.