At the age of 53, Dancing On Ice favourite Colin Jackson looks every inch the super-fit Olympian.

But the sporting icons winning smile as he skates with partner Klabera Komini hides a world of pain.

Because today, 110m hurdles hero Colin tells how track stardom has left him with the knees of an octogenarian.

The former world record holder is in constant agony, struggles to get out of his car and fears he could even end up in a wheelchair.

But he is now facing his biggest hurdle of all stem cell therapy to repair his damaged knees.

Colin says the treatment, which will begin next week, is the last roll of the dice to avoid joint replacement surgery.

Im in constant pain but you learn to live it with it, says the 1988 Olympic silver medallist and former World Champion hurdler.

Ive got the body of a man in his mid-30s but the knees of a man in his mid-80s. Ive had seven operations on my knees already four on the right knee and three on the left knee.

"I just cant face any more.

My knees lock up after long car journeys, and getting in and out of the bath is awkward.

It takes me ages to get going in the morning.

Colins glittering career left him with extensive damage to his kneecaps, cartilage, ligaments and tendons and he also has a degenerative condition that can make it difficult to get out of bed, let alone skate.

He needs to do a string of warm-up exercises every morning and has to take paracetamol and ibuprofen before every rink training session.

But Colin, a runner-up on Strictly Come Dancing in 2005, reckons his mental toughness is getting him through his sessions on the ice.

His family tried to talk him out of appearing on the hit ITV show, fearing he could suffer life-changing injuries if he falls.

But the will to win that once shot Colin to athletics stardom shone through.

I dont believe my knees will hamper my progress on the show, he says. That may sound contradictory because I am in pain, but Im in pain every day anyway, whether Im on the show or not.

My family is worried and just keep telling me to be careful but Im just not built that way. I love the challenge.

Right now, Ill compete and worry about things afterwards.

Colin is pinning all his hopes on starting the stem cell therapy and says hes praying for a miracle.

Its definitely the last roll of the dice to avoid knee replacement surgery somewhere down the line, he says.

Otherwise I will have to have more surgery at some stage. There is no doubt about that.

Im praying for a miracle because I really dont want knee replacements and I dont want to be in a wheelchair.

I want to be able to walk down the street when Im older. As part of his treatment, the BBC athletics commentator will have one million stem cells injected into each knee and more cells delivered afterwards via an IV drip.

The first session to prepare his body for the jabs will take place at Harley Street Stem Cell Clinic in London next week. Overall, it will cost him 25,000.

Colin is being treated by Dr Aamer Khan, who has specialised in the remarkable therapy since 2009.

Dr Khan said: Human stem cells are able to develop into different cell types that can be used to replace damaged tissue all over the body. They can drastically improve an individuals overall quality of life by reducing pain.

Colins condition will get worse if untreated and joint replacement is a real possibility if the therapy doesnt work. If it does, however, Colin could feel improvements in just four weeks and the full benefit after 12.

In the meantime, he plans to keep going for as long as he possibly can on Dancing On Ice a show notorious for falls and injuries.

So far this series, two professional skaters have been hospitalised because of training injuries and celeb contestant Denise van Outen dislocated her shoulder.

But Colin knows hes no longer the young athlete who thought nothing of pushing himself to the limit during his career.

When you are young, you dont worry about it, he says.

But when you get older, you realise the grief you have caused yourself. On a good day, the pain level is three out of 10 but on a bad day its a 10.

Being down on my knees is painful and I have to be careful with twisting and turning. But I still work out, I still go to the gym and do yoga and Pilates because I dont want to give in to it.

Before I train I will take ibuprofen so I dont exacerbate the problem.

But Im worried about walking on the pavement when its icy out, so I must be completely mad to be doing Dancing On Ice!

Colin says he was aware of what was coming during his career. I knew my knees were going to be a problem but I hadnt started to feel it until I got into my 50s, he says.

I still want an outdoor life. I still want to ski and go snowboarding. Im terrified my lifestyle will be badly affected but also that the everyday things might become difficult.

Colin says that these days, he cant even contemplate the sport that made him famous.

I couldnt clear a hurdle. Forget it. My knees wont let me, he says.

Ive attempted some small hurdles but the next day, my knees were really killing me. I just cant do those things any more.

When Dr Khan told me he may be able to help just before Christmas, I said, Lets give it a go. Ive got nothing to lose.

But this is a degenerative problem and there is huge potential I could end up in a wheelchair without a knee replacement or if the stem cell therapy doesnt work.

Colin realises people will probably think he is crazy for doing Dancing On Ice when the consequences of a fall could be so serious for him.

But he says: I feel that the other parts of my body are strong.

Being an athlete, Ive had so much treatment, injections and surgeries and still competed and had to perform so I am in the same mindset for Dancing On Ice. Its not new to me.

Every day as an athlete, I would perform with injuries and then hobble into bed but then go out the next day and do it all again.

It is something built into you when you have competed at the highest level, but Im not a fool.

Im not going to be like I was at 21 after the treatment, but if I can get 10% better, thats a huge amount of pain relief.

If the therapy doesnt work and Dr Khan says, Stop going to the gym, stop skiing and snowboarding because they are going to wear out your knees, then that would be difficult.

Its on my mind because being sedentary is not a good thing for me.

Its going to be a bitter pill if it comes to that but Im just praying the stem cells work their miracle.

More here:

Dancing on Ice's Colin Jackson to get stem cell op as he's got 'knees of 85-year-old' - Irish Mirror