BOSTON -- Just looking at Brandon Korona, you would never guess what he is about to do.

"I'm at peace with it. My family's at peace with it," Korona said. "And my friends think I'm crazy."

Brandon Korona CBS News

He asked doctors to cut off his lower left leg. Four years after it was crushed by a land mine in Afghanistan, he gave up on trying to save it.

"It was all rods, screws and some bone that didn't grow back right… It looked like a leg, but it wasn't a leg," he said.

Dr. Matthew Carty amputated Korona's leg in a six-hour operation at Brigham and Women's Faulkner Hospital in Boston. He used a new procedure that could reinvent the science of amputations.

Dr. Matthew Carty CBS News

"In the past all that has been asked of an amputated limb is to provide an adequate padding surface in order for a prosthetic to be adequately mounted," Carty said.

The new procedure connects the leg's front and back muscles to each other, allowing them to keep working together and communicate about it with the brain.

"And that is what enables us to walk normally without having to constantly look at our feet," Carty said.

The surgery is experimental. Korona is the first veteran and only the second patient to undergo this kind of amputation.

The goal is to connect Korona's stump to a new generation of smart prosthetics, now under development at MIT, that would move like a human foot.

"If we can elevate amputation to an equivalent form of salvage or an equivalent form of therapy, that in some ways is a major win for patients," Carty said.

Brandon Korona after his surgery CBS News

Two weeks after Korona's surgery, all that was left of his lower left leg were the screws that used to hold it together, in a plastic container.

"I'm happy that I have lost my leg and I'm ready to start recovering again," Korona said.

If the new procedure doesn't work, then he will use a standard prosthetic. Either way, the ruined leg that has been running his life for the last four years is gone.