Dr Tom Joyce, reader in biotribology at the University of Newcastle and fellow of the IMechE, was in Westminster last month – but not to visit the august environs of the institution HQ in Birdcage Walk.
Instead Joyce was subjected to a grilling by the science and technology committee of MPs, which was investigating the contentious area of the regulation of medical implants.
Joyce and other concerned engineers, doctors and surgeons had a victory to celebrate earlier this year when the British Hip Society ruled that a moratorium should be imposed on large-diameter metal-on-metal
This followed many months of campaigning and research that indicated that such devices were causing significant distress to some patients owing to wear of the implant and the release of metal into the body.
Symptoms experienced included severe pain, muscle and tissue damage, and attacks on bone. In some cases, the hips had dislocated, leaving the patient in agony. Surgery to repair the damage was difficult and could leave patients with long-term problems while relatively young, as the large-head metal-on-metal total hip replacements were originally aimed at patients in their forties and fifties. One manufacturer, De Puy, had been forced to recall a design two years ago.
The MHRA, the government agency responsible for ensuring that medical devices work, announced in February that it was changing the clinical advice on metal-on-metal hip replacements to make sure they were monitored once a year for the life of the device, instead of for just five years after the operation.
At Westminster, Joyce briefed the MPs on issues surrounding the pre-market testing and post-operation surveillance of metal-on-metal hip designs – where he believes many things could be done differently.
Joyce said he was glad that the politicians were taking an interest in the issue: “I thought it went pretty well, but there will be another session before a report, which could be out in the autumn. We’ll have to see what it says.”
He added that innovation should not simply be concerned with developing new products, but more effective ones.
“We all want to encourage innovation, but the important thing is to define what innovation means – and it shouldn’t just mean new products, it should mean better products. And if you do have better products then that actually leads to success in industry and to success as you face competition.”
Joyce called for the “substantial equivalence” system to be scrutinised more carefully and perhaps overhauled completely. Under guidelines laid down by the US Food and Drug Administration, a new medical device can be “substantially equivalent” if it has the same intended use and technological characteristics as the existing legally certified device, and so licensed.
“As I understand it, the substantial equivalence process is basically not up to the task. It needs to be changed entirely so we may have a move toward more clinical trials, or at least to collect more clinical data from a small group before any device is allowed to be widely used,” said Joyce.