Poster #1 In Vivo Biomechanical Evaluation of Third Generation Anterior Cervical Plate: A Radiostereometric Analysis

INTRODUCTION: The use of the anterior cervical plates has improved the postoperative fusion rates following multiple level cases. There are a number of plates available today and each plate addresses a different design philosophy. Fixed angle plates maintain a constant angle between the screw and the plate and have been implicated in stress shielding of the interbody graft resulting in pseudoarthrosis. Other plates have been designed to transfer more of the compressive force to the interbody graft by either allowing motion at the screw plate interface (variable angle plate) or allow linear translation of the vertebral body (dynamic plate). As of now, there is very little data comparing the settling characteristic of the different designs since it is nearly impossible to measure the postoperative micro-motion or settling in the cervical spine on routine radiograph. This prospective randomized study was designed to evaluate and compare the biomechanical properties of a variable angle plate to a dynamic plate in vivo using Radiostereometric Analysis (RSA).