Meet Oscar, the ground-breaking puss in bionic boots

A cat that had its back feet severed by a combine harvester has been given two prosthetic limbs in a pioneering operation by a UK vet. The new feet are custom-made implants that "peg" the ankle to the foot. They are bioengineered to mimic the way deer antler bone grows through the skin. The operation - a world first - was carried out by Noel Fitzpatrick, a veterinary surgeon based in Surrey.

The prosthetic pegs, called intraosseous transcutaneous amputation prosthetics (Itaps) were developed by a team from University College London led by Professor Gordon Blunn, who is head of UCL's Centre for Biomedical Engineering. Professor Blunn and his team have worked in partnership with Mr Fitzpatrick to develop these weight-bearing implants, combining engineering mechanics with biology. Mr Fitzpatrick explained: "The real revolution with Oscar is [that] we have put a piece of metal and a flange into which skin grows into an extremely tight bone."



"We have managed to get the bone and skin to grow into the implant and we have developed an 'exoprosthesis' that allows this implant to work as a see-saw on the bottom of an animal's limbs to give him effectively normal gait." Professor Blunn said the idea was initially developed for patients with amputations who have a "stump socket". "This means they fix their artifical limb with a sock, which fits over the stump. In a lot of cases this is sucessful, but you [often] get rubbing and pressure sores."

The Itap technology is being tested in humans and has already been used to create a prosthetic for a woman who lost her arm in the July 2005 London bombings. "The intriguing thing with Oscar was that he had two implants - one in each back leg, and in quite an unusual site," Professor Blunn said. He said that the success of this operation showed the potential of the technology.