The Cervical Spine Study Group anterior cervical plate nomenclature

The authors review historical and biomechanical aspects of anterior cervical plate (ACP) systems. They propose a novel classification system for ACPs based on the biomechanical and graft-loading properties of these systems. A retrospective review of the literature comprising both clinical and laboratory investigations regarding the ACP system was undertaken. Comparison of each system is considered in the context of the biomechanical attributes and graft-loading properties of each type of plate. Salient characteristics reviewed include restriction of screw backout, screw-angle variability, and mobility at the screw-plate interface. A new classification system for ACPs is proposed that primarily considers the ability of the construct to restrict screw backout, as well as the properties of the plate-screw interface--that is, the capacity for rotational or translational movement. A new classification system is presented that provides unified, biomechanically descriptive nomenclature. Using this nomenclature, the ACP devices currently available and those developed in the future can be uniformly categorized.