15. The spine stabilization device of claim 10 , wherein the housing has an exterior surface adapted to mount a connector.
10. A spine stabilization device comprising: a bone screw having a distal end adapted to engage a bone; a housing at a proximal end of said bone screw; a longitudinal bore in said housing; said bore being aligned with the bone screw and having an open end and a closed end; a hemispherical pocket at the closed end of said bore; a deflectable post having a proximal end, an elongated body and a distal end; the proximal end of said deflectable post extending from the open end of said longitudinal bore; a spherical retainer at the distal end of the deflectable post; the spherical retainer being received in the hemispherical pocket of the bore; a fastener which secures the spherical retainer in the hemispherical pocket and allows the deflectable post to pivot and rotate relative to the bone screw; and a compliant member positioned within the bore between the deflectable post and the housing such the compliant member flexibly resists pivoting of the deflectable post towards the housing and a limit surface associated with the housing and positioned to contact the deflectable post after a first angle of pivoting of the deflectable post away from alignment with the bone screw; and wherein deflection of the proximal end of the deflectable post after contact between the deflectable post and the limit surface requires at least double the load per unit of deflection than deflection of said post prior to contact between the deflectable post and the limit surface.