Patent ID: 8540754

Claim:
A spinal anchoring device, comprising: a bone screw having a threaded shank and a substantially spherical head that is truncated to form a flattened proximal surface; a receiver member having a proximal portion with opposed side walls that define a U-shaped recess therebetween for receiving a spinal fixation rod, and a distal portion having a cavity formed therein that seats the head of the bone screw such that the threaded shank extends distally from the distal portion of the receiver member; and a fastening element matable to the proximal portion of the receiver member such that the fastening element is effective to lock the spinal fixation rod in a fixed position relative to the receiver member with the spinal fixation rod directly contacting an inner surface of the receiver member, the bone screw being freely movable relative to the receiver member when the spinal fixation rod is locked in the fixed position relative to the receiver member by the fastening element.