Experiments to establish the safety of hip implants believed to have injured hundreds of patients were themselves seriously flawed, the High Court heard today.
Dr Frank Chan said failure to properly clean the metal-on-metal Pinnacle Ultamet system during laboratory testing could have caused friction within the joints that would have had “important clinical ramifications” for recipients of the device. A metal-on-metal hip implant
Low wear rates reported in trials the company carried out on its 38mm cobalt chrome heads were distorted by a surface buildup of proteins that should have been removed.
As a result, joints that were expected to experience a gradual loss of mass over millions of test cycles actually gained mass, making it impossible to determine precisely how much wear had actually occurred, Dr Chan said.