The training injury, less than one month before the Olympics, kept the then world No 2 at home in Australia.
Eight months later, Johnstone came out of rehabilitation, and he has notched up impressive international results this year.
"I've been good for a long time now. I've been fit and healthy since the end of January... Going into the season I was focused on the tricks I knew, doing them well, and amplitude. That's what the judges like to see. That is what got us those results," Johnstone said in Wanaka this week.
Johnstone is the top seed for the Winter Games halfpipe being held at Cardrona Alpine Resort on August 27.
The event has world cup status, but Johnstone will not be able to take the fight to White because the Olympic gold medallist is not attending.
Johnstone is clear about his ambition to win a gold medal, but the finely balanced nature of his stunt-packed sport means anything could happen.
This week, Johnstone was unceremoniously dumped from the New Zealand Open halfpipe competition after falling in qualifying rounds, and he will not compete today in the final.
"I was disappointed. It would have been nice to have gone through, but I fell pretty hard on my tailbone and that's giving me a little grief," he said.
Johnstone did not make the Winter Games podium in 2009 and expects stiff competition from Swiss high-flyer Iouri Podladtchikov (23), who has been hard on Johnstone's tail for the last six months and is no stranger to Cardrona's halfpipe.
Johnstone is not writing off Wanaka's top snowboard trio Mitchell Brown (24), James Hamilton (22) or Ben Stewart (19) either.
"Mitchell Brown is a great competitor. I've been riding with him for years. I was up riding with him two days ago and I am sure he's got a few tricks in the bag he hasn't revealed yet. And Ben Stewart and James Hamilton, they are definitely ones to watch."
Despite the disappointments of 2010, Johnstone is not thinking about the 2014 Winter Olympics.
"I just want to give this [the Winter Games] a crack," he said.
"I consider it a home event. I spend a lot of time here in the southern hemisphere season riding the parks. I've been coming here for three or four years, for most of my professional career."
Johnstone's coach Ben Alexander, of the Olympic Winter Institute of Australia, also has halfpipe riders Holly Crawford (27) and Jarryd Williams (21) under his wing.
Nathan Johnstone
- Snowboarder
• Age: 21.
• Winter Games events: Halfpipe, August 27-28, Cardrona.
• Results: Current FIS-ranked No 1 halfpipe snowboarder, first overall in 2010-11 world cup snowboard halfpipe, first overall in 2010-11 world cup snowboard freestyle, first in world snowboard championships at La Molina, Spain.
• Occupation: Professional athlete.
• Lives: Mona Vale, Sydney, Australia.
