Patent ID: 9060814
Filing Date: 2015-06-23
Classification: A61B

Abstract:
1. A bottom loading connector assembly for a polyaxial screw consisting of: a bone anchor having a spherical connector and a shank with at least one thread formed along the length of said shank and, a connector assembly having a first side wall and a second side wall each having a U-shaped opening, said connector assembly including an internal passageway having a wall that extends from a first end to a second end, the diameter of the internal passageway being greater than the diameter of the spherical connector at said first end and the diameter of the internal passageway at said second end being smaller than the diameter of the spherical ball connector, said internal passageway further including a first groove formed in said wall of the internal passageway, and a retaining ring positioned within said groove, wherein said groove includes an upper end wall, a lower end wall and a sidewall therebetween, said side wall being angularly positioned wherein the junction of the lower end wall and said side wall forms a first annulus having a first diameter and the junction of the upper end wall and said side wall forms a second annulus having a second diameter the second diameter of the second annulus is greater than the first diameter of the first annulus; wherein as the spherical connector is inserted into the bottom end of said internal passageway, the spherical connector is moved past said retaining ring which is initially expanded to allow the spherical connector to pass and once past the retaining ring will return to its unexpanded state and prohibit the removal of the spherical connector from the connector assembly.