Aksel Lund Svindal and Ted Ligety will miss next month's FIS Alpine World Ski Championships and sit out the rest of the season after undergoing surgery.

Norwegian Svindal, a two-time overall FIS Alpine Skiing World Cup winner, posted a message on social media revealing an exploratory operation had discovered that a meniscus ligament in his knee was no longer attached to the bone.

An Olympic and world championship gold medal winner, the 34-year-old suffered a season-ending knee injury 12 months ago and also battled with an Achilles problem in 2014.

"Here we go again ... ever since the Val Gardena downhill I've had a strange feeling in my knee," he wrote in a post on Instagram.

"Something didn't seem right. We did MRI scans and manual check-ups, but couldn't really determine 100 per cent if something was wrong or not. After trying the training runs in Wengen I made up my mind. Something's not right ... and we needed to figure out what. 

"Together with the medical team I took the decision to do another surgery. What they found was a meniscus that was no longer attached to the bone. That's no good in a downhill course ... Meniscus not attached means no function, and no function means every landing on a jump and every hit to the knee is painful. 

"The good part is that there are great chances of this being much better next winter. The bad part is that it's back to the crutches and no more skiing this winter... Hmmmm. Sounds familiar. But if it can be better next year, it's more than worth it:)."

Ligety, meanwhile, is also facing another period of rehabilitation. Like Svindal, the 32-year-old is a multiple Olympic and world championship gold medallist, who also suffered a serious knee injury in January 2016.

The American is set to undergo surgery to cure a back problem causing nerve pain in his left leg. 

"One last powder day with my wife before going under the knife," he said.

"Since Soelden, I have been dealing with severe nerve pain down my left leg that has not allowed me to ski at the level that I expect of myself. I have seen many doctors and therapists, undergone an array of treatments and therapies to no effect. 

"Unfortunately surgery (microdiscectomy) means my season is over and a chance to defend my GS title again at World Champs. 

"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. Thanks for your support. #illbeback."