A polyaxial orthopedic device for use with rod implant apparatus includes a screw having a bowl-shaped head and a coupling element. The coupling element has a rod receiving channel and an axial bore into which the head of the screw may be inserted. The interior surface of the bore is inwardly curvate at the lower end thereof to form a socket for polyaxially retaining the curvate head of the screw. In an initial position the screw head remains polyaxially free with respect to the coupling element. There is also a hemispherical insert which is seated on the top of the screw head, permitting it to rotate, but which may be compressed onto the head to permit the head of the screw to be locked in the bore. The rod is inserted into the channel and a top locking nut or set screw locks presses down on the rod and hemispherical insert to secure the assembly completely.