Metal-on-Metal Hip Problems May Be Detected with Ultrasound: Study

According to the findings of new research, ultrasounds could be used as an early detection system for failing metal-on-metal artificial hip systems, helping individuals who are not yet experiencing complications identify potential problems with their hip replacement.  

Last week, information on a new study was presented at the Hip Society Specialty Day Meeting in Chicago, where researchers from Canada indicated that they discovered ultrasound was useful in detecting pseudotumors often associated with metal-on-metal hip replacements.

Researchers looked at 40 patients who had undergone ultrasounds and a technique known as the metal artifact reduction sequence (MARS). They found that both techniques worked well, but ultrasound cost less. Savings where between $250,000 and $750,000 for every 100,000 patients that were screened via ultrasound instead of MARS.

Metal-on-Metal Hip Pseudotumors Linked to Early Failure, Other Problems

Pseudotumors are believed to be caused by metal debris shed as metal-on-metal artificial hip components rub against each other. Concerns have surfaced in recent years that this metallic debris could cause tissue damage and metal blood poisoning, also known as metallosis. In many cases, these problems have caused individuals to experience problems where their hip replacement loosens and ultimately needs to be replaced.

In January, the FDA released new guidance for metal-on-metal hip replacements. The agency told doctors that metal-on-metal hip replacement systems should only be used if other artificial hip implants were not appropriate, and called on manufacturers to prove that their implants were safe enough to stay on the market. Future metal-on-metal hip designs will have to undergo extensive human clinical trials before being made available for sale, the FDA decreed.

The agency also provided updated information for orthopedic surgeons, advising that doctors should pay close attention to patients with metal-on-metal hip replacements and to look for signs and symptoms of common problems associated with those artificial hips.

Lawsuits Over Metal-on-Metal Hip Problems

Thousands of individuals throughout the United States are now pursuing product liability lawsuits against the makers of metal-on-metal hip replacement systems, alleging that they failed to adequately research the design or warn about the risk of problems users may face as the metal components rub against each other.

In August 2010, Johnson & Johnson issued a recall for the DePuy ASR metal-on-metal hip system, after data suggested that as many as one out of every 8 implants were failing within five years. However, by the time the hip replacement was removed from the market more than 90,000 of the components were sold worldwide.

Johnson & Johnson now faces thousands of DePuy ASR lawsuits. So far this year, two cases have gone to trial, with one case in California resulting in an $8.3 million damage award and a second case in Illinois state court resulting in a defense verdict.

In addition, a growing number of lawsuits have been filed over other metal-on-metal hip systems, including the DePuy Pinnacle hip, Biomet M2A Magnum hip and Wright Medical Conserve Cup.