Researchers warn that new models of knee and hip implants appear to fail earlier and aren’t significantly more beneficial than older models, information that could affect hundreds of thousands of Americans in line to receive popular new models.
The results of the recent compilation study, released last week in The BMJ, revealed that newer implant designs marketed by their manufacturers as “innovative” in fact may be less durable. The safety of many of these popular new hip and knee implants “could be compromised,” researchers warn. The BMJ was formerly known as the British Medical Journal.
Recent high profile failures of a number of metal-on-metal hip implants spurred the study, led by Art Sedrakyan, associate professor at Weill Cornell Medical College in New York. Sedrakyan and an international research team worked with the U.S. Food and Drug Administration (FDA) to review the large collection of data from 118 previously release studies. Those earlier studies looked at data collected and reported on 13,164 patients.
“We did not find convincing high-quality evidence supporting the use of five substantial, well-known and already implemented device innovations in orthopaedics,” study authors reported. “Furthermore, none of these five technologies were found to be safer or to have better survival compared to the established implants.”
Higher Failure Rates, Regulatory Oversight
A number of device manufacturers marketed metal-on-metal implants as more durable and advanced in design than previous implants. But many patients and doctors found the implants failed at higher rates than those made of other materials such as metal and plastic or ceramic and metal.
Specifically, newer devices such as the now infamous DePuy ASR Hip and Zimmer NexGen Knee implant showed above-average failure rates. The culprit: metal particles flaking off and entering the blood and inflaming tissues.
Researchers focused on product safety after many brands of metal-on-metal hip implants failed early, causing catastrophic problems in thousands of patients – many required additional costly surgeries, called revision surgeries.
Experts blame lack of proper testing before putting devices on the market. They also call on regulatory agencies to step in.
The BMJ study highlighted “the limited regulatory oversight that exists in Europe, the U.S., and other countries regarding incremental device innovations,” researchers at Brigham and Women’s Hospital and Harvard Medical School in Boston wrote in an editorial response published in the same journal.
A number of physicians groups are already calling on the FDA to start a national registry to track devices. A national registry would provide meaningful data to compare the performance and safety of newer devices.
Other countries such as the UK, Sweden and Australia already have national implant registries in place. In fact, it was Australia’s joint registry that first clued surgeons in on the issues with metal-on-metal implants.
Some patients blame the implant’s manufacturers, leading to a deluge of lawsuits.
Hip and Knee Implant Recipients File Lawsuits after Failures
DePuy’s Pinnacle hip implant is one of the new devices promised to improve performance and last longer than older implants. Instead, a number of patients who received the device claim the implant caused them painful and debilitating injury.
Kathleen Herlihy-Paoli sued J&J after suffering from metal poisoning she said was caused by her Pinnacle hip. At the trial that began in Texas the first week of September, Herlihy-Paoli’s lawyers revealed internal emails showing that J&J planned to “keep quiet” about the problem with metal debris leaching from implants.
Dr. Thomas Schmalzried, who worked as a consultant for DePuy, warned executives that the release of metal ions was “major issue for metal-on-metal hips,” and that the potential harm to patients’ tissue was “alarming and concerning.”
Company executives deny the allegations.
The trial is ongoing in Texas, and Johnson & Johnson faces more than 6,000 lawsuits related to the implant.