Patent ID: 8075599
Filing Date: 2011-12-13
Classification: A61B

Abstract:
1. An orthopedic medical apparatus comprising: a receiver member having a longitudinal aperture, a channel for receiving an elongated member transverse to said aperture, a lower opening, and a groove communicating with said longitudinal aperture, wherein a lower portion of said longitudinal aperture includes a pair of opposed substantially flat walls; a bone anchor member having a longitudinal axis and a head, said head having a substantially part-spherical portion and at least two substantially flat portions, said flat portions being substantially parallel to said axis and substantially parallel to each other, at least a portion of said head being in said aperture; a crown member having a rounded lower surface, a pair of opposite substantially flat external surfaces, and a pair of opposite substantially cylindrical external surfaces extending from one of said flat external surfaces to an opposite one of said flat external surfaces to provide said crown member with an oblong disc configuration, said crown member being placed in said aperture so that said lower surface is adjacent said head of said anchor member, wherein said pair of opposed substantially flat external surfaces are received in said longitudinal aperture adjacent said pair of opposed substantially flat walls of said receiver member; and a retaining member at least partially within said groove and around at least a portion of said anchor member; and wherein said flat portions are arranged substantially parallel to said substantially flat external surfaces of said crown member and are also arranged substantially parallel to said pair of opposed substantially flat walls defined by said lower portion of said longitudinal aperture.