American freestyle skier Dylan Ferguson was forced to drop the opportunity to take part in the men's aerials event at the Vancouver Olympic Winter Games as the 21-year-old has not recovered yet after receiving surgery.

The United States Ski and Snowboard Association announced on Wednesday that Ferguson had acute appendicitis and required surgery on February 3.

The seventh finisher at last year's World Championships had been hoping to recover in time for the Games, but complications mean he will be unable to compete.

Ferguson will be replaced by Scotty Bahrke, whose best result was a fifth place in a World Cup event in 2008.

Scotty Bahrke's elder sister Shannon Bahrke got a bronze medal in the women's moguls last Saturday.