Patent ID: 9498254
Filing Date: 2016-11-22
CPC Classification: A61B

Claim Text:
1. A bone anchor assembly, comprising: a bone anchor having a proximal head and a distal threaded portion; and a receiver member having a proximal portion with opposed arms configured to receive a spinal fixation rod therebetween, the opposed arms of the receiver member defining a U-shaped recess having opposed planar surfaces for seating spinal fixation rods of differing diameters, the opposed planar surfaces extending at an oblique angle relative to a longitudinal axis of the receiver member, the receiver member having a distal portion having a polyaxial seat formed therein and configured to polyaxially seat the proximal head of the bone anchor, and the opposed arms having interior receiver threads, the receiver threads having a major diameter that increases in a distal-to-proximal direction when the opposed arms are parallel to each other, the receiver member having opposed relief slots formed therein, each slot having a first portion that extends parallel to the longitudinal axis of the receiver member and a second portion that is substantially perpendicular to the first portion; wherein the opposed arms are configured to move toward one another to cause a size of the polyaxial seat to increase and to cause the second portions of the slots to form a crescent shape, and the opposed arms are configured to move away from one another to cause the size of the polyaxial seat to decrease.