Patent ID: 7137984

Claim:
A plate system adapted for application to an anterior human spine and for contacting at least a portion of anterior aspects of at least two vertebral bodies adjacent a disc space, said plate system comprising: a plate having a mid-longitudinal axis and a length sufficient to span the disc space and overlap portions of the at least two adjacent vertebral bodies, said plate having a lower surface for placement against the vertebral bodies and an upper surface opposite said lower surface; at least two bone screw receiving holes extending through said plate from said upper surface through said lower surface; a plurality of bone screws, each bone screw insertable in one of said bone screw receiving holes, each bone screw having a head, a tip opposite said head, and a threaded shaft, said head having a maximum height parallel to the central longitudinal axis of said bone screw and a maximum diameter transverse to the central longitudinal axis of said bone screw, the maximum height of said head being less than one-half the maximum diameter of said head; and a locking element having a lower-facing surface adapted to cover a portion of said head of only a single one of said bone screws to prevent the inadvertent backing out of said single bone screw from one of said bone screw receiving holes, said locking element having an outer diameter, a central longitudinal axis, and an opening through said locking element along the central longitudinal axis.