Accident and Injury Lawyer Blog

On March 13, The Lancet, a top-notch British medical journal, published Failure rates of stemmed metal-on-metal hip replacements: analysis of data from the National Joint Registry of England and Wales.

The article is nothing less than a wholesale condemnation of metal-on-metal hip implants manufactured by orthopedic (orthopaedic, if you’re British) device companies:
Metal-on-metal stemmed articulations give poor implant survival compared with other options and should not be implanted. All patients with these bearings should be carefully monitored, particularly young women implanted with large diameter heads. Since large diameter ceramic-on-ceramic bearings seem to do well we support their continued use (emphasis added).
In 2009, one-third of all total hip replacements in the United States were metal-on-metal. There are over 500,000 patients in the U.S. now living with a metal-on-metal implant.

The article concluded that metal-on-metal total hip replacements failed and required subsequent replacement surgeries at an alarmingly high rate, particularly for larger metal “head” sizes. Overall, the failure rate was 6.2% after five years. Women seem to be more seriously affected, perhaps because they usually require larger implants. Ceramic implants - old school implants - had a much lower rate of revision.

The articles authors also pointed out that these conclusions likely could have been made with adequate pre-market studies and regulation. But medical device manufacturers have a very large financial incentive to push these devices out as soon as possible. First, so their investment in research and development is not wasted. Second, because the amount they will later pay in lawsuit claims is nothing compared to the massive profits they will get.

Though the article’s authors seem to support a worldwide recall on metal-on-metal total hip replacement devices, the Medicines and Healthcare products Regulatory Agency (MHRA—the British answer to the FDA) seems to believe that clinical data on the subject is “mixed.”

A total hip replacement basically involves a rod inserted into the leg bone (femur), which connects to a stem that has a ball at the end of it. The other component is a socket that is implanted into the hip. Implants may be metal, plastic or ceramic, or some combination. The implants discussed by the authors of The Lancet article have both a metal ball and a metal socket.

Some problems associated with metal-on-metal total hip replacements are a wearing of the device that releases metal particles into the body, sometimes into the bloodstream with catastrophic or fatal results.