A posterior vertebral stabilizer, which operates in tension and compression via a resilent member is disclosed. The ends of the stabilizer are attachable to pedicles of adjacent vertebrae so that the stabilizer adds stiffness to control flexion and extension of the vertebrae. Two such stabilizers may be used, and may be connected together by a crosslink designed to limit relative rotation of the stabilizers. Thus, the stabilizers may restrict axial rotation and lateral bending between the vertebrae, while permitting stiffened flexion and extension. The stabilizers help provide the stiffness of a healthy intervertebral disc.