Patent ID: 9572599
Date: 2017-02-21
CPC Classifications: A61B

Claim:
1. A spinal anchor assembly comprising: a bone screw and a receiver assembly moveably coupled to the bone screw, wherein the bone screw sits in a collar within the receiver assembly, said collar having a first side and a second side opposing the first side, wherein the first side and the second side are straight and parallel to each other, said collar having a third side and a fourth side opposing said third side, wherein the third side and the fourth side are rounded, and wherein the four sides define an inner cavity wherein said opposing first and second sides each include a D-shaped facet feature on an interior surface thereof facing said inner cavity; wherein said D-shaped facet feature includes a proximal straight edge portion and a distal curved portion, with a head of the bone screw is coupled to said curved portion of the D-shaped facet feature and is free to articulate along a single plane relative to said collar, further comprising a helical recess on said first side or said second side.