Lindsey Vonn, the most decorated female skier in US history, announced on Tuesday that she is withdrawing from the Winter Olympics in Sochi next month. Vonn crashed while competing in Austria last year tearing her anterior cruciate ligament and medial collateral ligament in her right knee. She also fractured her tibia in the crash and underwent knee surgery 11 months ago. Vonn had hoped to be ready in time to defend her 2010 Olympic gold medal in the downhill, but repeated setbacks will force her to sit out the games this year. In November, she reinjured her repaired knee during a training run and then strained it again last month. "I am devastated to announce that I will not be able to compete in Sochi. I did everything I possibly could to somehow get strong enough to overcome having no ACL but the reality has sunk in that my knee is just too unstable to compete at this level," Vonn said in a statement.