THIS is a story that can be found nestling within a knee or an ankle.

This is a tale that ranges up to the Indian borders of Nepal, to a hospital that grew to be a healing force after being set up under a mango tree by a Scottish doctor in the 1930s. It jumps to Dunblane where a young rugby player lies by the side of a pitch, his cruciate ligament ruptured after catching his studs on the turf.

This is a story about innovation, hope and charity. It is told in a small consulting room in a hospital on the south side of Glasgow by a surgeon who wants to change the way that treatment is given to injuries, and is determined to use that process to bring health to an Indian state where poverty is stark and the need great.

Professor Gordon Mackay, an orthopaedic surgeon, has been working on an internal brace to improve recovery from cruciate ligament injury for more than a year. He has now performed his first operation on a knee. The results are encouraging. "Briefly, the internal brace offers a way to think differently about sports injuries," he says. "My wife says it is incredibly obvious but my medical peers have had to be persuaded."

The principle behind the brace is to stabilise the internal joint, thus allowing tissue to recover without traumatic and invasive surgery. Professor Mackay puts it thus: "Surgeons usually accept that what we do is the gold standard and we find it hard to challenge that. We can repair, we can reconstruct, we can salvage joints. If you rip your knee apart, we can reconstruct the different components."

The internal brace offers another route. It keeps the knee stable, allowing a natural recovery. "If you fix the physiology early, then remarkably the healing starts immediately and it goes on," he says.

"The holy grail is to restore a normal joint. We have been trying to harness natural biology to heal. It is like servicing your car instead of crushing it."

The internal brace seems to make that an achievable goal.

This is where the story switches to Dunblane where Professor Mackay watched as one of his son's mates collapsed in a game of rugby. The cruciate ligament was injured. The boy had a problem. The surgeon had a patient for his latest technique. Instead of performing an invasive operation, taking tissues from elsewhere and drilling holes and using screws and other devices, Professor Mackay used keyhole surgery to insert a tiny piece of tape which acts as a brace over injured ligaments. The brace allows movement but supports the ligaments while they heal, speeding up recovery times.

The young player has recovered quickly and well. "His physiological testing afterwards showed the procedure was much better than a reconstruction. It had healed," says the surgeon.

The next step is to introduce the procedure on a wide basis, moving beyond sports injuries. There have now been inquiries about the technique from Venezuela, Korea, Japan and the United States.

Military rehabilitation centres and the National Health Service are also interested. The innovation was voted the most innovative and relevant development at a recent seminar attended by 1400 surgeons worldwide.

"It is a technique modification and it uses materials that are already tested as safe," says Mackay. "It means that it is ready to go as a procedure."

This brings the story to the matter of money.

"I have come to a reasonable compromise with the company that is producing the brace and I have said I am involved with a hospital overseas and I want to make sure the modest royalty I am claiming goes to a specific charity. We have come to that agreement,"

And this takes the story to Bihar and to the Duncan Hospital. In 1930, Cecil Duncan, an Edinburgh GP, was travelling through the region and decided to set up a small medical station. It grew. Its work was later helped enormously by two other Scottish GPs, Matt and Joanna Peacock.

"They were friends of my mother," says Mackay. "She died of cancer when I was six but they became sort of an aunt and uncle to me and I received Christmas cards from them until my forties. They also maintained their work with the Duncan Hospital."

The medical station had become a substantial building, tending to the needs of five million Nepalese across the border and six million Indians in the state. "But it was becoming a crumbling wreck, particularly after an American charity pulled out."

Mackay decided to put his effort and his money behind a rebuilding project and the first phase of that has been completed.

The ribbon was cut by the son of the doctor who had that charitable impulse under the mango tree. But this is only the beginning.

"I was asked to help some years ago and I have been totally blown away by the people I met. They live amongst a harshness of poverty in an area where there are health problems that are not addressed, never mind treated. The Duncan Hospital offers about 220 clinics for the population. I am not a crusader by nature but I am determined to do all I can to help," says Mackay, who will not put a figure on what he has donated so far.

He adds: "The internal brace offers a way to generate real life-changing funds for the hospital."

The rain beats on the window of Ross Hall hospital as the street scenes and noises of Bihar state play out on a portable computer. The story is unfolding before our eyes.

The next chapter may include a cast of recovering cruciate patients in Scotland and beyond and, wondrously, a tale of hope and health for the people of Bihar.