The BMX star and multiple world champion is smiling even though she's had seven operations in 12 months, spending more time in rehabilitation than on the bike last year.

Buchanan is smiling even though one false move, or trying to rush back to riding, could end her career if a metal plate and screws pop off her sternum again.

She's smiling even though husband Barry broke his leg at a time when he was supposed to be on nurse duties at home. But most of all, Buchanan is smiling because she's alive.

"I definitely saw some of my darkest days this year, but that's OK," Buchanan says from her California home.

"Because there's been plenty of lows, but there's also been some great highs. You've got to be able to flip the script, otherwise you'll be in a dark place.

"Maybe the universe was telling me to slow down, I don't know. I've had reality checks daily, so yes I am ready [for 2018] to end. Hopefully next year is smoother."

The Christmas period has given Buchanan a chance to reflect on a wild ride over the past year which almost killed her, tested her resilience and patience, and forced her to look at her life and career differently.

A rollercoaster is the only appropriate way for Buchanan to sum up this year. Injuries, hospitals, getting married, writing a children's book series and now injuries again.

It all started on New Year's Eve when she was involved in an off-road accident outside of Cooma and had to be rushed to hospital to treat bleeding around her heart, collapsed lungs, a broken nose and a broken sternum.

Buchanan was lucky to survive, but it was only the start of her journey. She has had three different titanium plates bolted into her chest to try to repair her sternum.

The last operation to put a bigger plate in is "the last resort" for fixing the broken bone. If that doesn't work, they could have to cut off part of her sternum and leave her lungs and heart vulnerable.

If that was the case, Buchanan's BMX dreams of world domination would be over. But she's choosing not to focus on that as she moves slowly around her home on the Christmas break, trying not to do anything to jeopardise her recovery.

Winning selection for the Tokyo Olympic Games is 2020 is still firmly on her radar and is the No. 1 goal. But until she is cleared to resume light training at the end of March, everything is about small steps.

"I can't lift my dog, I can't drive for three months, I can't lift grocery bags," Buchanan said.

"I can't even wash my hair right now, all the daily life stuff. The universe forced me to stop a bit. I live a crazy life and this was a reality check.

"Mum's [back in Canberra] trying to order groceries for us because Barry can't drive either. As tricky as it is, you've just got to get through it."

It hasn't all been bad. Buchanan married partner Barry at an intimate ceremony in Nevada and has used her injury time to write a book for children.

The memory of the crash will stick with Buchanan forever. It changed everything she had planned for this year, although cycling was the last thing on her mind when she was being rushed to hospital.

She found peace in meditation on the car ride to Cooma hospital and some spiritual meditation is helping her come to grips with everything that has happened since.

"In the past I've had that athlete focus and that's one of the big goals - to get the athlete side of me back," Buchanan said.

"If I can be an athlete again in 2019, that will be way better than the focus I've had on health and recovery this year.

"I'm trying not to let my head think about the Olympics or go too far ahead. The goalposts have changed so much this year

"The appreciation factor rises every time [you recover]. Right now it's about a quiet Christmas, preparing for 2019 and then my goal is the 2020 Olympics. I know it's do-able, I just don't know what it looks like getting there."

Even when Buchanan was fit to ride her bike last year, it didn't last long. She broke one of her fingers at a freestyle BMX event in China in November and needed surgery to repair the damage.

That injury was the trigger for Buchanan to also get her sternum checked, but she didn't get good news. Doctors discovered the screws and plate had popped out and was grinding in her chest.

To make things even more complicated, husband Barry broke his fibula during a backyard driving session and is struggling to move around the house as well.

"This time it seems solid. No popping or grinding," Buchanan said.

"I'd had issues all throughout the year with my chest, but I ignored it and just thought it was normal, something I'd have to live with.

"But I have to be patient now. There's wires and screws holding everything together. I have to be extra cautious with it because this really is the third and final attempt to [mend the sternum].

"If this doesn't work, the only other option is to remove the bottom of the sternum, leaving the bottom of my heart and lungs exposed a bit more. That would be the end.

"So I'm not thinking anything beyond this healing, and then I'll reset some goals so I don't rush too far ahead of myself."