A replacement hip is a prosthetic device that is used to restore proper function to a seriously injured or deteriorated hip joint. Total hip replacement is a fairly serious form of invasive surgery that removes the natural hip and replaces it with an artificial ball and socket joint. The majority of the artificial hips that are currently on the market consist of prosthetic structures made of solid titanium that pivot in a ball joint, consisting of a ceramic head within a polyethylene cup. Despite the invasive nature of total hip replacement surgery, it is a very successful form of orthopedic surgery, with 97 percent of patients experiencing significantly less pain and increased mobility after the procedure.
Although individuals from many different demographics may require total hip replacement at some point in their life, there are two groups of patients who are the most common candidates for these operations. The majority of patients requesting hip replacements are individuals with advanced forms of arthritis that cause considerable pain and loss of mobility. Most of these patients require the operation relatively late in life. Other individuals who typically require total hip replacement include those who have sustained a serious injury to the hip region, such as a hip fracture that has caused irreparable joint damage.
While total hip replacement surgery has the highest success rate of all forms of orthopedic surgery, there have been cases in which patients experienced serious complications due to manufacturing defects in the artificial hip. A particularly common problem with hip replacements lies in the lack of proper lubrication in the ball joint of the prostheses, causing unnecessary friction that can lead to complications down the road. The most serious complications arise when the ceramic head within the polyethylene cup detaches from the titanium hip or fails to graft properly with surrounding tissue. This can allow the components to migrate within the body, causing severe pain and a need for a revision surgery.
One of the common complications of a defective hip replacement is commonly referred to as a “squeaky hip.” This problem occurs when the ceramic textiles of a hip implant or joint replacement rub against each other without proper lubrication, causing a loud, squeaking noise when the body is in motion. While a squeaky hip can be quite inconvenient and frustrating over time, some of the more serious complications of a defective hip replacement include bone abrasion or chipping, a crunching sensation, chronic pain, and an eventual loss of hip function. In other cases, one particular model of artificial hips might require an unusually high percentage of patients to require revision surgeries, and medical experts are often at a loss to locate the actual design flaw that made a particular prosthetic hip less successful than others.
In September 2008, Portland Orthopedics, a manufacturer of medical devices located in Australia, issued a recall on all lots of its Margron DTC Hip Replacement System. The Food and Drug Administration (FDA) classified it as a Class 2 recall, the second most-serious classification available to the federal agency. The recall was issued due to the discovery in Australia that the number of patients requiring revision surgery following the implantation of Margron DTC Hip Replacement was higher than normal. The FDA also recommended additional patient monitoring in all American citizens who had already been implanted with the artificial hip, several of whom later required additional surgeries. In this unusual case, neither Portland Orthopedics nor the Australian or American agencies were able to ascertain the particular design defect in these devices that caused the need for revision surgeries. The two agencies could only ascertain that there was a direct correlation between the use of this particular model and the need for more revision surgeries than usual.
In August 2008, the FDA began receiving numerous complaints from patients and health care providers regarding the ceramic femoral head of the replacement hip systems produced by Indiana-based manufacturer Zimmer, Inc. Patients had been experiencing serious hip pain following their recovery from hip replacement surgery, which physicians discovered during revision surgeries was due to a ceramic head that had become loose from the titanium hip. In October 2008, Zimmer issued a voluntary recall of all affected ceramic heads as well as their Zimmer Duron Cups. Some 50,000 medical devices were included in the recall, many of which had already been implanted in patients who later experienced the same complications.