Lattimore had surgery Thursday and his rehabilitation should begin in the next few days, the university said.
The sophomore all-Southeastern Conference runner tore a ligament and suffered cartilage damage while blocking for a teammate on Oct. 15 against Mississippi State when a defensive player fell and rolled on his leg.
Lattimore has said he felt something buckle and instantly knew the injury was serious.
Lattimore ran for 818 yards in seven games this season before he was hurt. He ran for 1,197 yards and 17 touchdowns last season as he was named the 2010 SEC freshman of the year.