The World's First Artificial Limb (That's Really A Limb)

The artificial limb has come a long way. In ancient times, artificial limbs weren’t really designed to do the job of a limb. Rather, they were built to look like a limb; false hands were made that looked like a real hand in repose, but you couldn’t pick anything up with them. Honorable mention must go to a prosthetic big toe from ancient Egypt that would have enabled its wearer to walk barefoot and in sandals. 

By the middle ages attempts were being made in Europe to make prostheses that offered some level of function. And by the eighteenth century wooden legs, hook hands and similar devices were widespread. Inventive surgeons produced prostheses with harnesses that could allow artificial legs to bend and hands to grasp, prefiguring modern prostheses.

The Twentieth Century

Major advances often come in surgery thanks to warfare. We owe modern plastic surgery techniques to reconstructive surgery from the Great War and prostheses improved a lot then too. But they were essentially updated Renaissance models. Only post WW2 did prostheses become truly functional, and the advent of electronic control made them able to do things they never had before.They could pick things up. People with prosthetic legs could run. People with prosthetic hands could play games with them.

We shouldn’t underestimate the scale of the breakthrough this represented.

And when it became possible to control prostheses with the body’s own nerves, it seemed to many that the final bridge had been crossed.

Movement... But Something Was Missing

In fact, the most serious problem of prostheses remained, and it's easier to understand this by imagining a [prosthetic hand. You pick up a brick. That takes a certain amount of pressure. Then you pick up an egg. If it's your own hand, you know how much pressure to use dynamically. You don’t have to decide in advance, you can… feel it.

Even the best prosthetic hands and feet, arms and legs couldn't feel a thing.

Until now.

On June 8 2015 Professor Hubert Egger, leading a team of researchers in Vienna, revealed that they had produced a prosthetic limb that could feel. The limb, a leg, is the result of two processes.

The Feeling Foot

One is a surgical technique. Building on revolutionary surgical techniques that allow human nerves to control prosthetic limbs’ movements, researchers used the patient’s own nerves from his stump, rerouting them to his thigh.

Once that had been done, a modern lightweight prosthesis was fitted with sensors in its sole, allowing signals about weight distribution, foot placement and pressure to be transmitted via ‘stimulators’ to the nerves in the patient’s stump where it sits inside the shaft of the prosthesis.

The results are twofold: first, the patient has an unprecedented degree of control over the prosthesis. And second, the patient, an Austrian former teacher named Wolfgang Ragger, is really pleased with it.

“It’s like a second lease of life, like being reborn,” he told  AFP.

In one way, a final bridge really has been crossed. Unlike even the very best of previous prostheses, the new limb feels to Mr Rangger like a limb. “It feels like I have a foot again,” he continued. “I no longer slip on ice and I can tell whether I walk on gravel, concrete, grass or sand. I can even feel small stones.”

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A Revolution In Artificial Limbs: Feeling Real Sensation, Not Phantom Pain

Many amputees are troubled by “phantom limb pain,” sensations of pain and discomfort that seem to emanate from the limb that’s no longer there. This can be psychologically distressing, and feel like a cruel irony. But the level of actual pain can be really intense too. Many sufferers say they have trouble sleeping, heavy pain meds often don't touch it and the psychological toll of serious pain can be extreme. After all, the limb might be phantom but the pain is all too present, all too real.

Mr Rangger was a major sufferer. “I was barely able to walk with conventional prostheses,” he recalss, adding that he “didn’t sleep more than two hours a night and needed morphine to make it through the day.”

In addition to pain, amputees experience other phantom limb symptoms including tingling, cramping, heat and cold, and though formany people who have lost a limb the pain gradually decreases, the consensus is that if it continues for more than six months it’s unlike;ly ever to fully disappear and can remain very severe.

It’s been hypothesised that the pain in phantom limb pain is actually the sensation of nerves that are seeking the stimulation that should be there, but isn’t because the limb is no longer there.

And to judge by Mr Rangger’s experience, the new prosthetic method that has left him able to run, climb and cycle has borne out that hypothesis.

Mr Eggers points out that Mr Rangger “is a very differnt person now to the one I met in 2012,” when “he never laughedand he had these dark rings under his eyes.It was awful.”

Within a few days of the operation, though,the pain vanished. Mr Strangger doesn’t need morphine any more, and can sleep for the first time since he lost his leg.

As in Mr. Rangger’s case, phantom limb pain can mean a life disrupted by lack of sleep and pain meds as much as by the pain itself, and thre was little hope of medical intervention because the pain wasn’t due to any treatable cause. How can you treat something that’s by definition not there?

Mr Eggers points out: “People with amputations aren’t patients in the traditional sense, they aren't sick – they're just missing a limb.”

The Future Of Prosthetics

In light of the changes his new procedure has brought to Mr. Rangger’s life, Mr Eggers is seeking business funding for a program to begin producing his new prosthesis on a wider scale. Unit cost is about $11,000 to $33,000, but Mr Eggers sees applications for the device in the developed worlkd and oin the developing world, pointing out that post-surgery recovery is quick because moving nerves is relatively non-invasive, and there are no known health risks associated with it: ‘The only risk is that the nerves don’t reconnect properly and the feelings fail to return,” he says.

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It’s likely that Mr Eggers’ procedure or one like it will become standard practice for limb loss.