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.
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. 31. The spinal fixation system of claim 30 , wherein the connecting plate defines an opening at an end of the plate and wherein the opening has a bearing surface that mates with the proximal surface of the bone anchor.