A surgical instrument is configured to introduce a spinal fixation rod into a vertebral implant such that once the spinal fixation rod is engaged with the surgical instrument and the surgical instrument is put into a retention configuration, the spinal fixation rod cannot be removed from the surgical instrument until the spinal fixation rod is properly located and oriented with respect to the surgical construct and the surgical instrument is released from the retention configuration. The surgical instrument for introducing a spinal fixation rod includes a surgical instrument body with an actuator, and an engagement assembly at opposing ends and a transfer assembly extending between the actuator and the engagement assembly. The surgical instrument can also be used as part of a method for introducing a spinal fixation rod. Additionally, the surgical instrument can be part of a kit for introducing a spinal fixation rod, the kit including a plurality of spinal fixation rods of varying shapes and sizes.