Patent ID: 8388666

Claim:
A locking plate system for engagement with a bone, the system comprising: a) a plate including a plate hole with an inner wall; b) a split bushing including a radially exterior surface and a radially interior hole, said exterior surface including a plurality of frusto-pyramidal spikes, each of said spikes having four sides of substantially common shape and size, each of said four sides of a spike extends up from said exterior surface of said bushing by approximately 0.004 inch, said four sides are angled at an included angle of 75°, and a cross-dimension of a frustum of a tip of said spike is approximately 0.003 inch, and multiple spikes are provided about a line defining a circumference, said exterior surface of said bushing is sized to be in contact with said inner wall and said bushing is polyaxially articulatable within said plate hole; and c) a bone screw including a leading portion sized for extension through said hole in said bushing and into the bone and an opposite head portion sized to expand said bushing against the inner wall of said plate to cause said spikes to penetrate said inner wall and lock said bushing and said plate in a selected polyaxial position.