Abstract: An advanced spine fixation system includes a plurality of screw clamp assemblies preferably inserted through the pedicle and vertebral body at the vertebra. Each screw clamp includes a removable saddle assembly composed of two halves and each provided with apertures for the reception of rigid support rods which, in one form, form a parallelogram. In another form, the screw clamp receives a single rod, the clamp apertures and the rod being serrated for increasing the purchase. The apertures are proportioned to provide an interference fit with the rods to effect purchase between the saddles and the rods. In use, the screws and clamps are properly placed and a soft temporary master is formed which follows and replicates the contour of reference surfaces on the clamps. The temporary master is then used to form a master pattern which in turn is used to form the rigid rods to the determined contour. The rigid rods are then affixed to the clamp assemblies to provide the rigid support needed for spinal procedures.