Bears wide receiver Johnny Knox was placed on injured reserve and will miss the rest of the season after undergoing back surgery Monday. Knox was carted off the field on a stretcher in the first quarter of Sunday's loss to Seattle after the receiver -- scrambling to recover his own fumble -- absorbed a devastating hit from Seahawks defensive end Anthony Hargrove. He suffered a fractured vertebra, the team said, and surgery was performed to stabilize it. Knox's injury is not considered career-threatening.