Composite spinal apparatus

A composite surgical spinal fixation system including a bone bolt (11) having end portions (12) 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 section (14) for threadably receiving a nut (16) at a shaped, countersunk interface (42). As an alternate embodiment, a bone screw provides an upper enlarged head (46) with a lower coarsely threaded shank (44). A composite plate (17) having upper and lower surfaces and outer opposed edges is provided with an elongated slot (20) for accommodating a selected bone bolt or bone screw. The plate edges carry fine adjustments (27,28) extending between the upper and lower surfaces of the plate and a load transfer washer (35) interfaces the plate and the selected bone bolt or bone bolt (or screw) to the plate. The composite plate adopts a curved configuration via asymmetric ply lamination or by melt-forming. The curvature of the plate is dictated by the natural lordotic curvature of the patient's spine. The plate is comprised of either a plurality of laminal arranged in a specific ply sequence or a plurality of fibers or tows arranged through winding and/or placement. Electrochemical compatibility with the composite plate is ensured by careful selection of the materials comprising the attachment means and the washer mechanism.