Cats' Adventures 14

Oscar, the 'Bionic' Cat from Jersey, Channel Islands

Left-click thumbnails for enlargements (JavaScript should be enabled),
but please allow all images to load before doing so, or some may not display
(if this happens, use Refresh from your toolbar to reload the page)

In October 2009 a young black cat named Oscar was sunning himself in a field in Jersey, largest of the Channel Islands, when he was caught in the blades of a combine harvester. Both his back feet were severed, and when he was found about an hour later he had lost a lot of blood and was close to dying.

Oscar's local Jersey vet gave him first aid and bound up the wounds, which started to heal quite well. But while cats can lead quite a good life with only three legs, they cannot survive with just two, as they would be unable to walk, so it looked as though Oscar might well have to be put to sleep, because he would not be able to lead a reasonably normal life. However, the vet gave Oscar's owners — bank manager Mike Nolan and his wife Kate — some hope when he referred the cat to Professor Noel Fitzpatrick, a vet in Surrey, not far from London, who is a pioneer in prosthetic surgery. He runs a state-of-the-art practice that could rival many hospitals, with its own MRI room, a hydrotherapy pool and all modern veterinary facilities. In a recent operation he gave Storm, a Belgian shepherd dog, a unique prosthetic paw attached to a titanium rod implanted directly into Storm's foreleg, joining the skin with the metal prosthesis. It proved a great success, to the extent that Storm recently had to have the prosthesis replaced because he was leading such an active life that he had worn it out!

Professor Fitzpatrick felt there was hope for Oscar, although no animal had previously had two feet replaced. Custom-made implants (right) were attached internally to the ankle joints by drilling into the bones above where the feet had been amputated — a procedure that needed great care as a cat's ankle bones are small. The implants emerge from the skin rather like a pair of stilts. They are coated with hydroxyapatite, a material that imitates the way the bones of a deer's antlers mesh with soft tissue, and have a honeycomb structure that allows skin to bond to them, sealing them against infection. The flesh and bone bond to the bionic limbs well enough that they can bear weight and be flexible under the skin.

The operation to attach the implants lasted three hours; they cost £2000 each (about 3000 US dollars at 2010 rates). Technically they are called ITAPs — intraosseous transcutaneous amputation prosthetics — and they were developed at University College, London by biomedical engineer Professor Gordon Blunn and his colleagues.

Once Oscar's implants had been successfully inserted and had healed up, new paws were attached simply by screwing them into the end of the implants; the paws were developed at the University of Salford and were specially made with a degree of 'wobble' to allow Oscar to walk and run normally and even do a bit of climbing. They were brown, so had black adhesive tape affixed so they did not look too out of place on a black cat! These first paws fitted were made of rubber (left), but soon wore out; now he has four pairs of longer-lasting 'blade runner'-style ones of rubber and metal, which will not only be more durable but will allow him to run and climb more easily. They resemble the prosthetics used by Paralympic champion athlete Oscar Pistorius. However, the artificial paws will not be suitable for a full outdoor life, so Oscar will have to become more of an indoor cat, although he will be allowed out with a harness.

Oscar's story was released to the world in late June 2010; since the accident he had spent eight months at Fitzpatrick's practice. There's an excellent BBC video clip explaining the procedure and the fitting of the new feet. Then there is a good account, from which we have used information and a couple of images, at the Daily Mail. Oscar and his ground-breaking new paws were featured in a British TV series called The Bionic Vet in early July. In August 2010 Fitzpatrick's practice posted a video update of Oscar's progress: it shows him three weeks after his more advanced and improved 'blades' had been fitted and explains the thinking behind them.

Professor Fitzpatrick is adamant that he's not simply experimenting, or performing such operations 'because he can'. He says, 'I know where to draw the line. Animals are sentient creatures, with needs and wants. Doing a procedure just because it can be done is not ethical. I'll do it only if the perceived outcome improves the animal's quality of life.' And of course the technology could well result in benefits for humans, too, perhaps providing hope for people without hands or feet.

Further links