SYDNEY (XINHUA) - Two Australian orthopaedic surgeons have developed a 3D-printing technique to create high-tech ankle replacements.

Dr Tim O'Carrigan and Dr Mustafa Alttahir from the Limb Reconstruction Centre at the Macquarie University said their process provided "life-altering" joint replacements for patients who had suffered traumatic injuries, amputations, deformities, or arthritis.

Their breakthrough is achieved using specialised computer-aided design software which enables the surgeons to create a customised prosthesis unique to each patient.

In contrast, the traditional surgical treatment is ankle fusion, which involves removing the remaining joint cartilage and inserting screws between the bones, so the bones ultimately grow together.

"Fusions come with their own set of issues, including the potential for failure, and further arthritis from the increased wear and tear on the surrounding joints," Dr O'Carrigan said, noting that cartilage usually acted as a buffer between the bones, so its loss caused the bones to rub together painfully.

"Joints are designed to move, so we prefer to maintain that movement wherever possible by doing a replacement," said Dr O'Carrigan.

He gave an example of a recent patient who had previously undergone a conventional ankle operation.

That process, however, had led to the collapse of the joint with the talus, which is the large bone between the ankle joint and heel bone.

"In this case, we were able to replace the talus with a 3D-printed metal prosthesis that could articulate with the ankle replacement and fuse with the surrounding bone," Dr O'Carrigan said.

He said that after an ankle replacement with a 3D prosthesis, patients spend just six weeks on crutches while the new joint attaches to the bone, followed by another six weeks wearing a surgical boot, with full recovery taking about a year.

The surgeons said that all patients were assessed on a case-by-case basis, as unfortunately not every arthritic ankle was suitable for one of their pioneering joint replacements.

They noted that fusion could still be the best option for someone who had already lost too much of the "architecture of their ankle" or had a lot of scar tissue from previous operations or had extensive muscular damage.