A spinal stabilization system including an insert positionable in the channel of the housing of a poly-axial pedicle screw which allows for locking the housing of the poly-axial pedicle screw from pivotal movement through a clamping force generated by rotational engagement of a fastener with the housing while clamping a cord of a support construct in the housing of the poly-axial pedicle screw through direct contact of the fastener against the cord.