Hip implant tests seriously flawed, court is told

EXPERIMENTS to establish the safety of hip implants believed to have injured hundreds of patients were themselves seriously flawed, the High Court heard yesterday.

Dr Frank Chan said failure to properly clean the metal-on-metal Pinnacle Ultamet system during testing at Depuy’s UK headquarters in Leeds could have caused friction within the joints that would have had “important clinical ramifications” for recipients.

Low wear rates reported in trials the company carried out on its 38mm cobalt chrome heads were distorted by a surface build-up 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, said Dr Chan, a test supervisor.

Lawyers acting for more than 300 claimants argued that increased wear led to a release of a “large volume” of toxic metal debris into the bloodstream.