It is easy to forget what a rarity hip replacement surgery used to be. Today, people with artificial hips are ubiquitous. Direct costs of hip and knee replacements exceed $35 billion in the United States. More than 285,000 hip replacements are performed annually in the United States, and it is projected that this will increase to 4 million patients because of the aging population. Until very recently, hip replacements have been applauded as a wonderful, revolutionary way to get people back on their feet with less or no pain. But with this revolution came medical device makers looking to make as much money, and get as much market share, as possible.
The temptations for hip makers were extraordinary. Hip replacement surgery may be recommended in cases where hip pain limits daily activities, continues while resting (night or day), limits the ability to move or lift the leg, or in cases where pain relief is not provided by physical therapy, walking supports or anti-inflammatory drugs. Hip replacement surgery has a high rate of success, due to improvements in surgical techniques and technology. Total hip arthroplasty (total hip replacement) involves removing the damaged bone and cartilage and replacing it with prosthetic components. These components did not come cheaply, but health insurance companies readily admitted that this was the appropriate treatment for people with compromised hips.
Though many hip replacement surgeries are successful, there is a risk for infection, failure, and other adverse effects. Concerns have been raised in peer-reviewed publications relating to metallosis, the build-up of metal debris in soft tissues or blood. Reports are generally restricted to metal-on-metal devices or those constructed with acetabular polyethylene liner. Metal-on-metal devices often contain cobalt or chromium. Although the occurrence is rare (occurring in approximately 5.3% of patients), it is a serious complication associated with these devices. Metallic debris can occur because of malpositioning of the implant, subluxation, or jamming of the femoral head.
One study that got the attention of plaintiffs’ lawyers was a study that revealed that the metal-on-metal hips failed three times more often than other artificial hips. These artificial hips include models manufactured by DePuy (Johnson & Johnson), Wright, Stryker, and Zimmer.
How did these hip replacements get approved? Wouldn’t the problems with these hips have shown up in clinical trials? Incredibly, many metal-on-metal artificial hips were approved under less stringent regulations that allowed hip makers to piggyback to the market using the approval process of similar hip replacement products.
The problem, plaintiffs’ attorneys now believe from the science, is that tiny metal particles are released into the area from improper wear, which in turn, stimulate an inflammatory reaction as the body attempts to rid itself of the foreign matter. During this process, bone and tissue can degrade and can result in device failure. Metal particles can also be carried away from the location of the device by the lymphatic system causing systemic effects. It is possible that the formation of wear debris could exceed biological tolerances.
Metal-on-metal devices should not be used in patients with known metal allergies because of the risks associated with the wearing of the metal and debris formation. They may also be contraindicated in patients with end-stage renal dysfunction.
Metallosis often goes undiagnosed until revision surgery, which is awful. Getting the surgery in the first place is serious enough. A revision to a hip replacement is that much more difficult for the patient and their body. A radiology case report published in 2007 described cloudy radiodensities around the prosthesis indicated the presence of metallosis but is not always noticeable in radiographs. Thus other tests are required in combination with radiography to ensure the device is working properly and not putting patients’ health and well-being at risk. As such, blood monitoring of metal ions such as cobalt and chromium should become a standard of care in the monitoring of patients with metal-on-metal devices.
Your doctor should be able to order appropriate blood tests and additional diagnostic tests to determine your risk for metallosis. This monitoring should be done throughout the life of your replacement device. If it is found that metal ions in the blood are increased, it may be a sign that the device is failing, and replacement surgery to correct the problem may be required. The Medicines and Healthcare products Regulatory Agency (MHRA) in England issued a statement at the end of February recommending that physicians monitor their patients who have had certain metal-on-metal hip replacements on an annual basis. The MHRA was the first regulatory agency in 2010 to issue a warning about metal-on-metal hip devices. It is likely that the FDA will issue a similar statement in the coming months.
If you are having problems with your metal hip replacement, and think it could be related to your device, call us at 800-553-8082 and we will try to give you your options and steer you in the right direction. You can also chat with us about your potential hip replacement lawsuit on line.