A bushing for a bone screw assembly includes a distal portion, a receiver portion, and a proximal portion. The distal portion includes a distal engagement surface that engages with a head of a bone screw. The receiver portion receives a fixation rod. The proximal portion includes a proximal engagement surface that engages with a locking member and a deformable portion that deforms from a first configuration to a second configuration based on a force applied by the locking member.