An orthopaedic device is disclosed for mechanical intercoupling between selected vertebrae of the human spine and an elongated surgical rod. The device includes a block-shaped member having upper and lower surfaces, front and rear surfaces, and left and right side surfaces. A central cylindrical bore extends through the block-shaped member between the upper and lower surfaces. A longitudinal slot extends between the upper and lower surfaces, and from the front and one side surface of the block member into the central bore. The central bore and longitudinal slot serve as a yoke into which a section of the surgical rod may be placed, the width of the slot being slightly larger than the diameter of the rod. A short, hollow, cylindrical sleeve member, with internal diameter slightly larger than the diameter of the rod, is adapted for slidable movement over the rod and into the central bore of the block-shaped member to provide capture of the surgical rod. A recessed, hollow socket extends part way into the block-shaped member between the central bore and the rear surface of the block-shaped member. An aperture extends from the bottom of the socket out through the rear surface. The recessed socket serves to retain the support and head of an angularly adjustable, removable anchor attachment member, i.e., a hook member or surgical screw, the hook member being designed for providing limited angular movement within the socket in a plane perpendicular to the axis of the surgical rod.