Patent ID: 8574272

Claim:
A bone plate assembly comprising: a bone plate including an upper surface and a lower surface opposite the upper surface, the lower surface adapted to contact bone, the bone plate having at least one opening extending therethrough, the at least one opening including an annular non-threaded sidewall and a non-threaded lip adjacent the lower surface of the bone plate, the lip extending inwardly from the sidewall and defining a planar surface extending from the sidewall towards a center of the opening; and at least one bone screw including a shank and a head, the shank being repositionable with respect to the head when the head is secured in the at least one opening in the bone plate, the lip configured for engagement with the head when the head is secured in the at least one opening; wherein the shank includes a uniform outer diameter and a first continuous helical thread adapted to engage bone and the head includes a tapered configuration and a second continuous helical thread for coupling with the lip of the at least one opening of the bone plate, wherein the head of the at least one bone screw is constructed of a material which is harder than a material of the lip of the at least one opening in the bone plate.