Dr Sam Axelrad brought the skeletal keepsake home to Texas as a reminder that when a badly injured North Vietnamese soldier was brought to him, he did the right thing and fixed him up. The bones sat in a closet for decades, and when the Houston urologist finally pulled them out two years ago, he wondered about their true owner, Nguyen Quang Hung.

The men were reunited on Monday at Mr Hung's home in central Vietnam. They met each other's children, and grandchildren, and joked about which of them had been better looking back when war had made them enemies. Mr Hung was stunned that someone had kept his bones for so long, but happy that when the time comes, they will be buried with him.

"I'm very glad to see him again and have that part of my body back after nearly half a century," Mr Hung said by telephone Monday after meeting Dr Axelrad. "I'm proud to have shed my blood for my country's reunification, and I consider myself very lucky compared with many of my comrades who were killed or remain unaccounted for."

Mr Hung, 73, said American troops shot him in the arm in October 1966 during an ambush about 46 miles from An Khe, the town where he now lives. After floating down a stream to escape a firefight and then sheltering in a rice warehouse for three days, he was evacuated by a US helicopter to a no-frills military hospital in Phu Cat, in central Binh Dinh province.

"When I was captured by the American forces, I was like a fish on a chopping-board," Mr Hung said. "They could have either killed or spared me."

When Mr Hung got to Dr Axelrad, then a 27-year-old military doctor, his right forearm was the color of an aubergine. To keep the infection from killing his patient, Dr Axelrad amputated the arm above the elbow.

After the surgery, Mr Hung spent eight months recovering and another six assisting American military doctors, the former soldier said. He spent the rest of the war offering private medical services in the town, and later served in local government for a decade before retiring on his rice farm.

"He probably thought we were going to put him in some prisoner-of-war camp," Dr Axelrad said. "Surely he was totally surprised when we just took care of him."

As for the arm, Dr Axelrad said his medic colleagues boiled off the flesh, reconstructed the arm bones and gave them to him. It was hardly common practice, but he said it was a reminder of a good deed performed.

The bones sat in a military bag in his closet for decades, along with other things from the war that he didn't want look at because he didn't want to relive those experiences.

When he finally went through the mementos in 2011, "it just blew me away what was in there," Dr Axelrad said at a hotel bar in Hanoi early Sunday, hours after arriving in Vietnam with his two sons and two grandchildren on Saturday evening. "That kind of triggered my thoughts of returning."

It had taken a little luck for Dr Axelrad to reunite Mr Hung with his amputated arm. He traveled to Vietnam last summer - partly for vacation, but also to try to find the man.

He said he wasn't sure Mr Hung was still alive, or where to begin looking for him. By chance, Dr Axelrad toured the old Vietnam War bunker at the Metropole Hotel in downtown Hanoi. His tour guide was Tran Quynh Hoa, a Vietnamese journalist who took a keen interest in his war stories, and went on to write an article in a widely read local newspaper about the doctor's quest to return the bones to their owner.

Mr Hung said his brother-in-law in Ho Chi Minh City read the article and contacted the newspaper's editors.

Ms Hoa, now a communications officer for the International Labour Organisation, arranged Monday's reunion in An Khe, near the coastal city of Qui Nhon, and served as an interpreter for the veterans.

"It's just time for closure," Dr Axelrad said a day before the meeting.

Mr Hung was surprised to be reunited with his lost limb, to say the least.

"I can't believe that an American doctor took my infected arm, got rid of the flesh, dried it, took it home and kept it for more than 40 years," he said.

Mr Hung served Dr Axelrad and his family lunch, shared memories and reflected on all the time that had passed. Dr Axelrad said he was pleased to learn where and how Mr Hung had been living for so many years, and to meet his children and grandchildren.

"I'm so happy that he was able to make a life for himself," Dr Axelrad said.

Vietnam is now a country full of young people who have no direct memory of the war, which ended in 1975 and killed an estimated 58,000 Americans and 3 million Vietnamese. But the war's legacy persists in the minds of combat veterans who still are processing the events and traumas they witnessed in their youth.

John Ernst, a Vietnam War expert at Morehead State University in Kentucky, said he knows of a few American veterans who have travelled to Vietnam to return personal items to former enemy soldiers as a way to bring closure.

"It is a fascinating phenomenon," Mr Ernst said by email on Sunday. "I always wonder what triggers the decision to make the gesture."