29. The spinal fixation system of claim 1 , wherein the distal bone anchor portion is a polyaxial screw that includes a head that mates with the rod receiving portion and a bone screw portion, whereby the bone screw portion pivots about a point at the head of the bone screw portion.
30. The spinal fixation system of claim 29 , wherein the proximal surface of the rod receiving portion is spherical and has a radius of curvature that extends from the point about which the bone screw portion pivots.