Keen sportsman Thomas Green, 13, suffers from a condition which has left him with severe arthritis in his left leg and has endured 20 operations to try and ease the pain.
Now, having been told an amputation is his best hope, he is determined to see this as a new chapter of his life. Rather than dwell on his loss, he has chosen to focus on what options a prosthetic leg could bring - including the opportunity to one day run with a blade.
And he is so positive about what the future holds that his family hosted a 'farewell' party on Friday - to his old life as much as his leg.
"I'll be able to walk, and do what everyone can do," he said. "I've had problems for years. Anything that can change that will be alright. I'm positive. I have to be able to leave this behind."
Thomas has been walking with crutches for the past four years. The teenager suffers from something called a 'venous malformation', a network of veins behind his knee that have bled into the joint and caused severe arthritis.
From an early age he has been unable to bend his left knee and any physical activity causes him intense pain. In October he was advised by specialists that amputation was his best option.
Admitting it was a difficult decision to make, he said his worry was eased when he started to see how having a prosthetic leg could change his life.
At the moment, one of his few chances to take part in sport is through the charity Panathlon, which helps thousands of disabled and SEN students.
At Panathlon’s Yorkshire Regional Multisport Final in York last week, he led his team to victory to take home gold and he won the shot put, boccia and table cricket events.
“At the end of a Panathlon event I feel like it’s a big achievement for me, because I can’t really do many sports," he said. "This is one I can do, and I love it.
“I’ve had so many operations to try and make it better but they’ve not worked. I’m feeling nervous about the operation, but afterwards I’ll be able to walk pain free. I’m looking at it positively – or trying to!”
And when his mum suggested a party, complete with Elvis impersonator, to mark this step, he thought it would be the best way to show everybody how it wasn't something to be sad about.
"I actually thought she was joking," he said. "But then I thought it was a good idea. It's both a celebration and a goodbye party."
His mother Adele and father Matthew have booked caterers and have had a cake made in the shape of a leg.
"We thought it would be quite a good way to celebrate him strarting this next part of his life," said his father.
"He's been struggling on crutches for he last three or four years. Hopefully he will be able to throw them away, and walk on two feet again.
"We thought it's something to celebrate rather than dwell on it for negative reasons."
Mr Green, a father of five, says Thomas has always been a keen sportsman and Leeds Rhinos fan, watching his big brothers play rugby.
"The past few years have been difficult for him," he said. "I see him with all his friends, out on their skateboards and bikes. He goes out, but he has to follow them on crutches.
"While they are going up ramps or doing wheelies on their bikes, he has to stand and watch. It's heartbreaking. He hasn't been able to do the things that his friends can.
"An amputation might sound like a bad thing. But it's an opportunity, a positive opportunity. It's a new start in his new life.
"We're so proud of him. He's so brave. It's a very brave decision for any 13-year-old to have to make."