American skier and Olympic champion Lindsey Vonn has confirmed that she will not be able to defend her downhill title in Sochi next month after failing to recover from a knee injury.

Vonn needed surgery to reconstruct her knee ligaments early last year, and suffered a setback when she failed to finish the World Cup downhill in December.

She is one of the most high profile winter Olympians having won an Olympic Gold in 2010 as well as multiple World Championships.