A pedicle screw assembly including a bone fastener having a lower end for engaging bone and an upper end remote from the lower end; a head having a rod-receiving channel attached to the upper end of said bone fastener; a spinal rod insertable into the rod-receiving channel of said head, said spinal rod having an outer surface extending between first and second ends thereof, wherein at least one of the first and second ends has a reduced diameter section. A spinal rod having an outer surface extending between a first end and a second end thereof; wherein the outer surface of said spinal rod has a reduced diameter section at least one of the first and second ends.