A metal-on-metal hip implant made by Johnson & Johnson failed in more than a quarter of cases by the sixth year after the devices were installed, according to a U.K. medical registry.
The ASR Acetabular implant from J&J’s DePuy Orthopaedics Inc. unit was removed or replaced 29 percent of the time after six years, compared with a 9.5 percent failure rate for all metal-on-metal implants, the National Joint Registry of England and Wales said in its 2011 annual report.
Findings by the registry last year led New Brunswick, New Jersey-based J&J to recall the ASR devices. The world’s biggest hip maker faces more than 2,000 lawsuits related to its implants. Regardless of manufacturer, metal-on-metal implants need replacing more often than other types, according to the U.K. registry.
“There appears to be a sharp increase in the risk of revision at around six years after primary surgery for the metal-on-metal group although more data is needed to confirm this finding,” the registry report said.
The revised figures should be viewed in a broader context, Lorie Gawreluk, a spokeswoman for DePuy.
Evaluate ‘With Caution’
“The six-year revision rate should be interpreted with caution because it is based on a small number of cases,” she said in an e-mail. “The five-year data is more statistically robust given the much larger patient population from which it is drawn.”
The report found 17 percent of the ASR Acetabular implants were removed or replaced after five years, Gawreluk said.
In the seventh year after implantation, overall removal rates for hip implants were 4.7 percent, according to the registry. The rate for metal-on-metal implants, which consist of metal balls and sockets, was 14 percent compared with 3 percent for cemented devices.
Use of metal-on-metal devices in England and Wales has declined to 5 percent of procedures in 2010 from 15 percent in 2007, the registry said.
The registry says it has the world’s largest joint database with 1.1 million records covering hip, knee and ankle joint procedures in England and Wales.