The Ivory Coast international was injured in the 2-1 win over Hull on October 19 and last week manager Roberto Martinez revealed it was more serious than first thought.
Everton have confirmed Kone, who turns 30 next week, will need surgery and although no timescale has been placed on Kone's recovery the club believe it will significantly impact the part the forward plays in the rest of the season.
Source: PA
Source: PA