Hip Replacement Implant Makers Get Good News and Bad News

Seattle, WAIt has been a month of good news/bad news for the makers of metal-on-metal hip replacement devices. The good news is that a recently released study suggested that there was no increased risk of cancer in patients who received metal-on-metal hip replacement devices. The bad news is that the US Food and Drug Administration (FDA) plans to hold hearings into the hip implants, to see if the benefits of the hip devices outweigh the risks.

The cancer study, published in the British Medical Journal (4/3/12), examined data from people who received metal-on-metal hip replacements and found that patients who received the implants were at no greater risk of cancer after seven years than patients who received different hip replacement devices or no hip replacement. Cancers included in the study were malignant melanoma, prostate and renal tract cancers.

The study follows a previous report, published by the British Medical Journal and the British Broadcasting Corporation, which said that patients who received the metal-on-metal hip implants may have been exposed to toxic metals, caused when metallic debris came loose from the implants and was absorbed by the patient's tissue.

Researchers note, however, that there were limitations to the most recent study, including that patients who receive the metal-on-metal implants tend to be healthier than patients who receive other implants, because the metal-on-metal implants are designed to last longer and be used by active patients.

Despite the intention for metal-on-metal hip implants to be more durable than other hip replacement devices, some metal-on-metal devices have been subjected to a recall, thanks to data indicating a high failure rate in the devices. In response, the Food and Drug Administration announced it was convening an advisory panel for June 27 and 28, to determine whether to strengthen the rules that allow new devices to be sold in the US. According to The New York Times (3/30/12), the advisory panel meeting will examine the failure rate of the devices, risk factors and complications associated with metal-on-metal hip devices.

Some reports estimate that the metal-on-metal hip devices are failing at a rate of about 12 percent by five years. Traditional hip implants are expected to last around 15 years. Lawsuits have been filed against the makers of certain hip replacement devices, alleging the devices were defectively designed and manufactured, putting patients at increased risk of revision surgery and injury.