The defender was taken from the field on a stretcher in his side's 1-0 defeat to Southampton on February 11, after colliding with team-mate Steve Harper.
McShane underwent exploratory surgery on Monday that ruled out a micro-fracture, and is set for another operation in a fortnight.
Hull boss Steve Bruce said the Republic of Ireland international will still need a significant amount of time to recover from ligament damage, but added the injury could have been worse.
"The operation was as good as it could be," Bruce told the club's official website.
"He had that on Monday and he'll have a major operation in two weeks' time, but the news is as good as we could have hoped for considering the damage to the ligaments.
"He hasn't got a micro-fracture so the doctor has told me, so it's as good news as we could have had, but he's still going to be out for a long time.
"He won't play again this season and we're hoping that he’ll be back for the start of next season, but until the next operation it’s still a doubt."
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