Ted Ligety, a two-time Olympic skiing gold medalist and a five-time world champion, announced Monday that he planned to have a back operation that would end his World Cup racing this winter and could cloud his prospects for the Winter Olympics next year in Pyeongchang, South Korea.

Ligety, the defending Olympic and world champion in the giant slalom, wrote on his Instagram account that he had been suffering from severe nerve pain in his left leg since October and that it had inhibited his performance.

“I have seen many doctors and therapists, undergone an array of treatments and therapies to no effect,” Ligety wrote.

He added: “This has been tough to accept especially after last season, but on the plus side hopefully this surgery will alleviate the back issues I have dealt with over the last few years. I will be back strong and fast again.”