'Bionic' limb breakthrough made

The breakthrough, developed by researchers at UCL, allows the prosthesis to breach the skin without risk of infection.

The team says early clinical trials have been "very promising". …

The work paves the way for bionic limbs which are controlled by the central nervous system.

The technique, called Intraosseous Transcutaneous Amputation Prosthesis (ITAP), involves securing a titanium rod directly into the bone.

The metal implant passes through the skin and the artificial limb can be directly attached to it. …

Risk of infection, which could be caused by bacteria passing from the external limb through the rod to the bone, is avoided because the skin tissue meshes around the rod to form a seal. …

To work out how to attach live tissue directly to metal, the scientists from the UCL Centre for Biomedical Engineering, led by Professor Gordon Blunn and Dr Catherine Pendegrass, looked at how deers' antlers can grow through the animals' skin without infection. …

Dr Paul Unwin, managing director of Stanmore Implants Worldwide, a medical devices company that worked in collaboration with the scientists, said: "The mobility of tissue is a big factor; you don't want the tissue to rip away from the piece of metal, so you need a structure under the skin that will allow the dermal tissues to attach into the metal.

"What we had seen in the deer antlers was that it is very much to do with the structure and shape of the bone, and the porosity of the bone.

"The tissue attaches in with long fibres, and it is like anchors attaching directly into it."

He said that early clinical trials, which had taken place at Mount Vernon Hospital, Middlesex, on a small group of patients who had lost fingers or thumbs had been very encouraging.

The next stage, he added, would be to carry out trials on upper and lower limb replacements. …

He said that the technology could be widely used for thumb and forefingers in a few years, and upper and lower limb replacements using this method could be in place in five years. …

BBC News Online