The procedure was successful and the prognosis for Knox's football future is positive. No timetable has been set for his return.
Knox was taken off the field on a stretcher after taking a hard hit during Sunday's game against the Seattle Seahawks.
On the Bears' second possession of the game, Knox caught a 17-yard pass over the middle of the field. Knox then lost control of the football and a scramble for the ball followed.
Seattle defensive lineman Anthony Hargrove came flying in and hit Knox up high. The wide receiver's head snapped back due to the force of the hit.
"Johnny has total movement throughout his body, has total use of all his extremities, which is good," Bears head coach Lovie Smith said after the game. "We're doing tests right now, but he has total movement. He is not paralyzed or anything like that."