A method for stabilizing a spine includes providing a
coupling element having upper and lower ends, a rod receiving opening adapted to receive an elongated stabilizing rod, a bore extending through the lower end and a conical-shaped seat surrounding the bore adjacent the lower end; providing a
fastener having upper and lower ends, a head having a
radial surface, and at least one anchoring element between the lower end of the
fastener and the head; assembling the
fastener with the
coupling element so that the lower end of the fastener passes through the bore of the
coupling element and the
radial surface of the head engages the conical-shaped seat. The method also includes anchoring the fastener to bone; moving the coupling element relative to the fastener for capturing the elongated stabilizing rod in the rod receiving opening; and urging the captured stabilizing rod
toward the head of the fastener so that the rod contacts the head and forces the
radial surface of the head against the conical-shaped seat of the coupling element for locking the coupling element from further movement relative to the fastener.