An improved method and guide wire assembly used in a system, set of instrumentation and method comprising the combination and use of plural pedicle screws, a rod for connecting pedicle screws in a relatively rigid manner, and instrumentation to optimize insertion of the rod into the pedicle screws, the assembly having a guide wire and instrumentation to grasp a medial portion of the guide wire to pull the medial portion through all the pedicle screws and connecting the loop to the end of a fixation rod, whereby one end of the guide wire is mounted to a pedicle screw, all the screws are implanted into the vertebrae, and the rod subsequently guided into the pedicle screws by pulling the guide wire loop back through the pedicle screws, all using minimally invasive surgical incisions.