On April 9, 2013, James Mason's life changed forever. During an argument, his stepfather, Bob Gambuti, tried to stop him from getting into a car after Mr Mason had been drinking.
"He grabbed onto me, I grabbed onto him, he pulled my leg out and we fell back and his neck broke," says Mr Gambuti.
"My body had swollen up everywhere," says Mr Mason. "My hands were huge from what I could see and I didn't know what was going to happen at that point."
"I think the most devastating part of the whole process was the first day that they lifted him out of a bed and nothing moved, just his head," says Mr Gambuti. "That really hit hard. At that point I really wanted to go jump off a bridge."
Mr Mason was left a quadriplegic, with just the slightest ability to move his arms.
Mr Gambuti researched experimental treatments and applied to a trial by Stem Cells Inc at New York's Mount Sinai Hospital. It would involve opening up Mr Mason's neck, removing his vertebra and injecting stem cells into the damaged portion of his spinal cord.
The surgery, performed by Dr Arthur Jenkins, took four hours. Doctors have tracked the progress of Mr Mason and five other patients in the trial -- all with the most severe spinal cord injuries.
"My body temperature's been a lot better regulated," said Mr Mason three months after the surgery. "My wrist has gotten a lot stronger. I'm able to grasp around a lot other things."
After six months he said it had almost doubled how much he had got better.
"I've got sensation back into my feet. I can feel pressure onto them, throughout my legs. And they've noticed that I have a little bit of movement into my hips now."
Stem Cells Inc reported that four of the six patients in the trial experienced improvement in both motor strength and function. Dr Jenkins, who is not affiliated with the company, has continued to monitor Mr Mason.
"My two cents is it worked, that this actually changed his neurological recovery and function, that his functional improvement is from the stem cells that were injected," says Dr Jenkins.
"It feels great, but I'm just ready to get to the next goal," says Mr Mason.
Mr Mason believes the stem cells accelerated his recovery. Though both he and his stepfather say the accident drew them closer, Mr Gambuti's healing is a process.
"It's odd and it's tough and people say, 'I'm sorry.' Don't be sorry," says Mr Gambuti. "I still have him here."