The British Medical Journal today published a feature article profiling additional problems with DePuy’s Pinnacle metal-on-metal hip implant. This article comes a year and a half after DePuy recalled a similar implant–the ASR implant–and at a time when many are questioning why the Pinnacle implant has not yet been recalled.
The Journal reports that DePuy altered its design of the Pinnacle by making the femoral head larger, but making the stem that it sits on much shorter. DePuy made this change without conducting any clinical trials to prove that the change was safe or effective. DePuy also did not conduct adequate post-marketing studies to detect long-term problems with the design change.
Experts say that these design changes likely are are responsible for the release of high levels of toxic cobalt and chromium into the body. Despite this risk, the regulators in the US and Europe did not spot the changes or warn doctors and patients of the potential dangers.
Dr. Tony Nargol, a consultant surgeon at the University Hospital of North Tees, said he first told DePuy about damaged tissue in metal-on-metal Pinnacle patients in 2008. Since then, Dr. Nargol has recalled all patients who have the Pinnacle metal-on-metal implant and he found that at least 75 of the 97 Pinnacle patients already have had a failure related to metal debris.
Internal DePuy documents reviewed by the British Medical Journal show that as early as 2005, DePuy was aware of the damage that could be done to patients by metal-on metal-implants. E-mails reviewed by the British Medical Journal show that Japanese surgeons warned DePuy in 2009 that metal debris from the Pinnacle was harming patients. And in 2010, a senior DePuy executive said in an internal document that he was “concerned” about problems with the metal-on-metal Pinnacle and similar implants. “I feel the problem is emerging as more serious than first thought,” he wrote.
Despite all of this, DePuy continues to sell these implants to this day.