According to ABC News, a Denver woman who was experiencing all-over symptoms like itching and headaches only recent discovered she was allergic to the cobalt in her hip implant.
According to the news report, Paula Spurlock, 50 years old, suffered from allergy symptoms for nearly two years before her doctors were able to discover the source of her discomfort. Not only did she have pain in the hip area and migraine headaches, but she itched all over. Despite regular allergy tests, nothing came up until a PET scan hinted that her implant was potentially malfunctioning. At that point, Spurlock saw an allergy specialist who looked for reactions to metals and other materials used in artificial hip joints.
The results of these tests showed that Spurlock was allergic to cobalt, a metal used in a many hip implants. She had never experienced metal allergies before, so hadn’t thought that could be the source of her symptoms. She went on to state that the metal-on-metal hip became defective within about two years of implantation, and that as a result, it deposited tiny shards of metal into the tissues surrounding her joint, which eventually spread to her bloodstream. She went through revision surgery to have the implant replaced with a ceramic implant.
This isn’t the first time that questions have been raised about potential allergic reactions to metal hips. A case-controlled study published in 2009, for instance, noted that the prevalence of metal allergy may be higher in patients with implant failure. Though the study eventually concluded that the risk of revision was not increased in patients with metal allergies, it still raised the question of potential reactions to these implants.
During a presentation to the American Academy of Orthopaedic Surgeons at the 2012 Annual Meeting/Orthopaedics Research Society symposium, Joshua J. Jacobs, M.D., noted, metal allergy [with] othopedic implants has been well documented in isolated cases.
He added that significant symptoms seemed to be much more common in metal-on-metal total hip replacements than in knee replacements or metal-on-plastic hip replacements. Symptoms may include a rash that appears after implantation and may recur later, as well as pain and swelling. Responses to the allergic reaction may also lead to pseudotumors, tissue damage and death, stiffness, and unexplained pain.
In January 2013, the FDA warned that metal-on-metal hip implants have unique risks in addition to the general risks of all hip implants. They added that the release of metal particles inside the joint can cause bone and/or soft tissue damage, which may then lead to pain, implant loosening, device failure, and the need for revision surgery. All-metal hip implants include the recalled DePuy ASR, the DePuy Pinnacle all-metal option, the Zimmer Durom Cup, Wright Conserve, Smith & Nephew Birmingham, Stryker Rejuvenate, and Biomet M2A.