A spinal stabilization system includes a connecting rod and a bone screw. The connecting rod includes an elongate rounded section, an elongate head portion, and a neck portion connecting the elongate rounded section with the elongate head portion. The bone screw includes a head portion defining a slot, a shank extending longitudinally from the head portion, and a cap. The slot includes a leading end portion configured to receive the elongate rounded section of the connecting rod and a trailing end portion defining a planar surface. The cap is configured to enclose the planar surface of the trailing end portion of the slot and secure the connecting rod in the slot to the bone screw.