Although an artificial hip can occasionally make a variety of noises, until Stryker, a medical products company, began marketing its ceramic hip replacements, squeaking was rare. With the advent of these ceramic hip replacements, however, hundreds of patients using the product have discovered that their hips are making squeaking noises very frequently. This squeaking, consumers claim, is interfering with their daily life leading to dozens of people having surgery to replace the noisy hips. Some have also decided to sue Stryker, the innovator and leading manufacturer of the product, although the company has been said to be slow in taking their patients’ concerns seriously. Last year, the Food and Drug Administration (FDA) issued a warning to Stryker claiming the company had failed to take the steps needed to prevent squeaking and other problems. To make matters worse, Stryker recalled ceramic hip parts made at its factory in Ireland due to the parts not meeting sterility specifications. Stryker, however, claims none of the underlying problems in the warning letter from the FDA or in the recall reflect the problems causing squeaking, which occurs in only about 1% of the products.
While ceramic artificial hips are promoted as being more durable than previous models, the squeak leads patients to wonder if there are any other more serious problems with the product. Many patients and doctors believe this squeak can be a signal that the joints are wearing out prematurely, resulting in the patients getting another hip replacement operation, the very operation the ceramic hip replacement is supposed to be preventing. Other doctors fear the implant will shatter leading to inflammatory shards in the hip. Some investigators looking into the problem say the squeaking could be associated with the extreme flexing of the implants. X-rays determined many of the squeaking hips were perfectly aligned and the squeaking was not directly related to hip pain or other sensations patients might encounter.
More than 250,000 Americans receive total hip implants annually. This procedure has a success rate of over 90%, based on patients’ achieving fairly pain-free mobility after recovery periods that range from a few months to a year. A recent study of 143 patients, who received ceramic hip replacements, showed about 10 of them, or 7 percent, developed squeaking. On the other hand, the control group of 48 patients with hips made of metal and plastic had no squeaking. http://www.nytimes.com/2008/05/11/business/11hip.html?pagewanted=2&_r=2&ref=health&adxnnlx=1210601838-81RWULhGcEXImSs2lJ/cfQ
Whether these hip replacements are just a noisy inconvenience or something more, in the nature of a safety problem, remains to be shown. Regardless, for the amount of money patients pay for these hips, and the extremely invasive and painful nature of the surgery and rehabilitation involved, these folks should not have to deal with this type of engineering issue, much less be subjected to another surgery to eliminate the problem.