An Austrian man has voluntarily had his hand amputated so he can be fitted with a bionic limb.
The patient, called "Milo", aged 26, lost the use of his right hand in a motorcycle accident a decade ago. After his stump heals in several weeks' time, he will be fitted with a bionic hand which will be controlled by nerve signals in his own arm.
The surgery is the second such elective amputation to be performed by Viennese surgeon Professor Oskar Aszmann.
The patient, a Serbian national who has lived in Austria since childhood, suffered injuries to a leg and shoulder when he skidded off his motorcycle and smashed into a lamppost in 2001 while on holiday in Serbia.
While the leg healed, what is called a "brachial plexus" injury to his right shoulder left his right arm paralysed. Nerve tissue transplanted from his leg by Professor Aszmann restored movement to his arm but not to his hand.
A further operation involving the transplantation of muscle and nerve tissue into his forearm also failed to restore movement to the hand, but it did at least boost the electric signals being delivered from his brain to his forearm, signals that could be used to drive a bionic hand.
Then three years ago, Milo was asked whether he wanted to consider elective amputation.
"The operation will change my life. I live 10 years with this hand and it cannot be (made) better. The only way is to cut this down and I get a new arm," Milo told BBC News prior to his surgery at Vienna's General Hospital.
Milo took the decision after using a hybrid hand fitted parallel to his dysfunctional hand with which he could experience controlling a prosthesis.
Such bionic hands, manufactured by the German prosthetics company Otto Bock, can pinch and grasp in response to signals from the brain that are picked up by two sensors placed over the skin above nerves in the forearm.
In effect, the patient controls the hand using the same brain signals that would have once powered similar movements in the real hand.
The wrist of the prosthesis can be rotated manually using the patient's other functioning hand (if the patient has one).
World first
Last year, a 24-year-old Austrian named Patrick was the first patient in the world to choose to have his hand amputated, again by Professor Aszmann, and a bionic replacement fitted. He lost the use of his left hand after being electrocuted at work.
He can now open a bottle quickly and tie his own shoelaces.
"My reaction was 'Oh my god, I've got a new hand!'," he told BBC News.
"I can do functions which I did with my normal hand with the prosthetic arm," he said, recalling his response to first being fitted with a bionic hand.
"I think it was very cool - I did not do things with my hand for three years and then you put on the new hand and one moment later, you can move it. It's great."
Patrick is already testing a new hand, which its makers say will give him much greater movement. The hand has six sensors fitted over nerves within the lower arm, rather than the two on his current prosthesis.
Multiple signals can be read simultaneously, enabling the patient to twist and flex their wrist back and forward, again using the same brain signals that would have powered similar movement in the real hand.
Professor Oskar Aszmann prefers to calls these elective amputations "bionic reconstruction" and has been working closely with Otto Bock, who have a research and production facility in Vienna.
Before the first operation, the professor held a symposium to discuss the procedure, to which senior surgeons and a theologian were invited.
He believes elective amputations are the best option for patients who have lost hand movement and who have no hope of regaining that movement through surgery.
"You see a patient come to you with a tremendous need for hand function and it's only a thought away to come to the next conclusion," he said.
"If the patient cannot address his only hand and I can change his anatomy in a way so he can communicate with an artificial hand, then of course I'll just take away what's there and provide a technological hand for him."
But Professor Aszmann has faced opposition in some quarters, with senior colleagues even requesting he cancel this latest operation - requests the professor promptly rejected.
He said the alternative for patients like Milo would be years of pointless surgery.
"Milorad is now 26 years old and he wants to go on with his life. To biologically reconstruct a hand for him would be a never-ending story and in the end he would still have a non-functional hand.
"It is in the patient's interest to provide him with a solution he can live with properly and successfully, and so I have no problem with cutting off his hand."
In the event, the amputation itself passed without incident.
Scar tissue from a previous operation was removed and then the hand cut off with a pneumatic saw. Tissue was then taken from the hand and transplanted to the wrist to provide a cushion for the prosthesis.
Speaking from his hospital bed following the surgery, Milo was a little drowsy, but as positive as ever.
"I feel good," he said, his bandaged arm lying on a cushion besides him.
"I'm happy that it's over and look forward."
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