In August 2010, Johnson & Johnson subsidiary, DePuy, announced a recall of its ASR XL Acetabular System and ASR Hip Resurfacing System, two hip replacement components used in total hip replacement surgery. In the months that have followed, this blog has told readers about metallosis, one of the possible symptoms resulting from implantation of the DePuy ASR hip units. Metallosis is an allergic reaction by the body to metal ions contained in hip implant metal components such as High Carbon Content Steel, a cobalt-chromium alloy. But metallosis is not the only symptom of the defective DePuy hip implants.
Among the additional complications from defective hip implants are loose cups and pseduotumors, as well as fractures and friction transfer problems around the pelvis area. These symptoms can cause inflammation and loss of mobility, including loss of the ability to walk. Needless to say, these symptoms result in pain and frustration for many patients.
Several medical experts have stated that the DePuy hip implants were “too shallow” for implantation to begin with. They say the lack of depth within the hip implant units are one of the primary causes of patients’ complications. These experts have suggested that even the most skilled of doctors are likely unable to implant the flawed hip component in such a way to avoid complications. This means that the blame for DePuy rests primarily with its manufacturing process and not with surgeons. Predictably, DePuy denies that its ASR hip implants are too shallow and has attempted to shift responsibility to physicians.
The reason the ASR hip implants were designed with a shallow cup to begin with was to allow for greater mobility of the hip joint. However, because the cup insufficiently covered the adjoining hip ball component, the cup could not properly distribute the forces of the ball evenly when a patient stood up. Instead, the shallow cup often over concentrated the forces generated by a standing patient to the edges of the cup, otherwise known as “edge loading.” As a result, metal-on-metal friction was created between the prosthetic ball and cup, resulting in fracture and the aforementioned metallosis. In a healthy hip, friction is eliminated either by biological fluids or by a properly working hip implant in the case of post-operative hip joints.
Although DePuy may have intended the shallow cups for the purposes of allowing for greater joint mobility, the opposite result occurred for many patients. Furthermore, DePuy had knowledge for years that its shallow cup design was flawed and was causing a higher rate of revision surgeries than normal.
As experts continue to examine the recalled ASR hip implants, they will discover even more details surrounding the DePuy hip units’ imperfections. As those imperfections are increasingly understood by experts, plaintiffs attorneys will have a growing knowledge of the forthcoming DePuy ASR hip implant litigation.
The Berniard Law Firm has been closely following all developments stemming from the DePuy hip implant recall and will continue to do so indefinitely into the future. Attorneys at Berniard Law Firm have been consulting with experts in efforts to better understand the exact flaws of the DePuy hip implants. Consequently, Berniard attorneys have developed a thorough understanding of this issue and know how to effectively counsel clients through this complicated legal matter. Contact the Berniard Law Firm today for any questions concerning yours or your loved one’s hip implant legal issues.