Thousands of British hip replacement patients are suffering from DePuy implants made incorrectly at a factory in Leeds, the Daily Telegraph reports. DePuy has admitted “an error in the measuring techniques” when making the metal-on-metal implants, according to the London publication. At least two types of hip implants were affected by production issues, both metal-on-metal versions that are no longer used. DePuy said the measuring issue was related to the manufacture of a metal-on-metal liner called Ultamet, which was part of its Pinnacle line until 2013. The manufacturing issue arose because parts were measured when hot – they had been heated by the polishing machines and so were expanded, and were a different size when returned to room temperature, the Telegraph quotes DePuy as saying in papers submitted to the High Court. A spokesman said DePuy investigated when it became aware of the issue in 2008, concluding there were no safety issues but also removing from the manufacturing line the equipment that caused the issue, according to the Telegraph. The company refused to answer a series of detailed questions about when it uncovered the problem and how it responded, the paper also states. Any mismatch in the size of the parts of an implant could lead to higher wear rates, causing debris to break off and enter the bloodstream, it quotes health and orthopedic experts in the U.K. as saying. Artificial hips made by DePuy have been surgically implanted in more than 350,000 patients in the U.K., with more than 20,000 of those being metal-on-metal devices, according to the report.
