American skier Lindsey Vonn says she has "no regrets" after a crash in the women's downhill competition at the Winter Olympics resulted in a "complex" broken leg which will require multiple surgeries.

The 41-year-old was already racing with ruptured ligaments in her left knee when she struck a gate 13 seconds into Sunday's run in Cortina.

Thrown off balance, Vonn was left screaming in pain after falling and was treated on the slope for a lengthy period before being airlifted to hospital in Treviso.

The 2010 Olympic downhill champion, competing at a fifth and final Games, later had surgery on a fractured tibia.

"Yesterday my Olympic dream did not finish the way I dreamt it would," she said in a post on Instagram on Monday.

"It wasn't a story book ending or a fairytale, it was just life. I dared to dream and had worked so hard to achieve it.

"While yesterday did not end the way I had hoped, and despite the intense physical pain it caused, I have no regrets.

"Standing in the starting gate yesterday was an incredible feeling that I will never forget. Knowing I stood there having a chance to win was a victory in and of itself."

The 2010 Olympic downhill champion tore her anterior cruciate ligament (ACL) while competing just nine days before the Games began.

The two-time world champion says the torn ACL and her previous injuries, including a partial right knee replacement, "had nothing to do with my crash whatsoever".

Vonn's decision to race has led to widespread praise for her bravery but also criticism about the dangers and potential risk of permanent damage.

"It always was and always will be an incredibly dangerous sport. And similar to ski racing, we take risks in life," she said.

"We dream. We love. We jump. And sometimes we fall. Sometimes our hearts are broken. Sometimes we don't achieve the dreams we know we could have. But that is also the beauty of life; we can try.

"I hope if you take away anything from my journey it's that you all have the courage to dare greatly. Life is too short not to take chances on yourself. Because the only failure in life is not trying.

"I tried. I dreamt. I jumped."

Vonn's American team-mate Keely Cashman said people who had criticised her for competing "do not know what's going on".

"People that don't know ski racing don't really understand what happened yesterday," downhill skier Cashman said on Monday.

"She hooked her arm on the gate, which twisted her around. She was going probably 70mph, and so that twists your body around."

Italy's two-time world champion Federica Brignone also defended Vonn, saying: "If it's your body, then you decide what to do, whether to race or not. It's not up to others. Only you."