Bone fixation apparatus

A surgical spinal fixation system includes a bone bolt having first end portions that are adapted to be surgically implanted into a patient's spine at first and second spaced apart positions and a central portion of the bone bolt defining a load transfer surface, the bone bolt having a second upper threaded sections for threadably receiving a nut at a shaped, countersunk interface. As an alternate embodiment, a bone screw provides an upper enlarged head with a lower coarsely threaded shank. A plate having upper and lower surfaces and outer opposed edges is provided with an elongated slot for accommodating a selected bone bolt or bone screw. The plate edges carry fine adjustments extending between the upper and lower surfaces of the plate and a load transfer washer interfaces the plate and the selected bone bolt or bone screw for distributing load (and reducing stress) from the bone bolt (or screw) to the plate.