‘Depuy knew hip implants had faults’
Lawyers claim up to 260,000 people could be affected by ‘defective’ metal-on-metal implants
FAULTY hip implants were 100 times more likely to fail than other devices, and maker Depuy “knew they were defective”, the High Court heard yesterday.
Lawyers acting for 341 claimants made the allegation on the first day of a compensation battle over Depuy’s metal-on-metal Pinnacle Ultamet system, which was finally withdrawn in 2013. Robin Oppenheim, QC, said it could have harmed to as many as 260,000 people worldwide, with up to a 100-fold increase in the number of metal-on-metal implants requiring “revision” after 10 years.
He pointed to a 1995 memo which warned that metal implants were “working well for a period of time” before wearing down and releasing “a large volume” of toxic metal debris into the bloodstream.
Depuy’s non-metal on non-metal joints were also three-to-five times more likely to require revision over the same period than other manufacturers’, he added. The trial will see lawyers argue that their clients were affected by the release of metal particles from the implants, with symptoms including pain, difficulty walking, swelling and numbness or loss of sensation in the leg.
The arrival of a new generation of artificial hip implants in the late 1990s saw their use increase dramatically, with more than 20,000 patients fitted with the metal-on-metal Pinnacle system between 2000 and 2011. It was finally discontinued in 2013 due to “low clinician use”, three years after safety fears were first raised publicly.
A document written by Dr Graham Isaac, a senior engineer based in Depuy’s Yorkshire factory, went on to explain: “It is clear from the literature the survivorship of cobalt chromium [the materials used in metal implants], metal-on-metal prostheses in the past have been far from satisfactory.
“Simulator testing of such components suggests their performance is as unpredictable as ever, working well for a period of time before suffering a sudden catastrophic breakdown of the bearing surface accompanied by a release of a large volume of wear debris.”
The combination of metal components was “likely to give rise to toxic levels of metal under clinical conditions”, Dr Isaac added.
Bozena Michalowska-howells, of solicitors Leigh Day, said: “After five years working on these cases I look forward to our clients finally having their day in court. They believe that the Pinnacle device has failed to deliver on the level of safety they were entitled to expect.
“As a result of this failure, they have suffered pain and early revision surgery which we believe would have been avoided had they been implanted with a conventional hip product.”
A spokesman for Depuy said: “The device is backed by a strong record of clinical data showing reduced pain and restored mobility for patients suffering from chronic hip pain. We are committed to the long-term defence of the allegations in this litigation.”
The case is expected to last until the New Year.