Some thought the MS Mondraker professional may not walk again, let alone ride and now race his bike.
And after an enforced recovery at home in Hawke's Bay, Macdonald is enjoying his first winter in more than a decade.
"My health is good, and my back is coming right. To be honest I feel like I am fitter than ever before.
"I had the rods taken out a week before lockdown, which has given me so much more movement although there is one rod left in the vertebrae that I burst.
"I am so lucky. It could have been a lot worse. At the time I was healthy, fit and strong, which was key."
After an initial surgery in Canada, he was flown to the Burwood Spinal Unit in Christchurch where he began his recovery.
"I just can't say enough for the staff there – their patience and professionalism. And to my girlfriend who had to put up with so much."
Macdonald was able to training fully for most of lockdown and since lockdown he has been back training fully in the gym and on his road bike.
"I have been doing the local club racing with the Ramblers and thought I would give nationals a crack seeing it was in Hawke's Bay. Mind you I was not expecting to have all those top elite riders there. That will make it fun."
Macdonald aims to return to the professional mountain bike scene. "I don't know if there will be any racing this year – I am not too sure. If it happens it happens - I have not missed any racing to get to that stage."
One positive from Covid-19 has been a boost for the mountain bike industry.
"The biking industry has done best out of everyone. People locked inside now appreciate the chance to do something outdoors and mountain bike was one of the real beneficiaries. I hope people appreciate the outdoors more now and continue to ride their bikes."
No doubt there will be plenty of support for Macdonald when he lines up in the senior men's road race at Waipukurau on the final day of the championship on Sunday.