A system for performing a less invasive surgical procedure and, in particular, devices and methods for spinal fixation. The system comprises dilation tool(s), at least one working/insertion cannula, a plurality of screws, at least one fixation rod for connecting the screws, and a rod inserter. The dilation tool(s) may be used to dilate an incision made in a patient to form an opening. Thereafter, a drill may be used to form holes in the vertebrae. An insertion cannula may be attached to a screw and inserted into the opening. The screws may be polyaxial screws and may be inserted into the vertebrae using a screwdriver. An operator may then move the insertion cannula to manipulate a head portions of the screws such that the head portions may be aligned to receive a fixation rod. A rod inserter may be used to insert a fixation rod into the head portions. After the fixation rod is in place, it may be locked to the screws, thereby fixing the system in place on the spine.