Patent ID: 9095379
Filing Date: 2015-08-04
Classification: A61B

Abstract:
1. A bone anchor assembly comprising: a bone anchor having a proximal head and a distal shaft configured to engage bone, the distal shaft having a central longitudinal axis, the proximal head having two opposed flat side surfaces oriented parallel to the longitudinal axis of the distal shaft and two curved surfaces each interposed between the flat side surfaces; a receiving member having a proximal end and a distal end, the proximal end having two spaced apart upright arm defining a recess for receiving a spinal rod therebetween, the distal end having a bore therethrough, the bore having a proximal opening at the recess and a distal opening sized to allow insertion of the proximal head of the bone anchor therethrough; a compression member configured to be positioned within the receiver member proximal to the proximal head of the bone anchor, the compression member having a top surface configured to receive the spinal rod and having a first protrusion and a second protrusion extending distally from a bottom surface of the compression member on opposite sides thereof so as to form a first continuous gap extending between the first and second protrusions along a first side of the compression member and a second continuous gap extending between the first and second protrusions along a second, opposite side of the compression member; and a closure mechanism configured to engage with inner surfaces of the arms of the receiving member to secure a spinal rod within the recess, wherein the bone anchor is positioned so that the flat side surfaces of the proximal head align with the first and second protrusions, respectively, and the two curved surfaces of the proximal head are positioned within the first and second continuous gaps, respectively.