6. The implant of claim 1 , wherein said deflection rod comprises an inner superelastic rod and an outer polymer shell.
1. A spine implant comprising: an anchor adapted to be inserted into the bone of a patient, the anchor having a longitudinal axis; an anchor head extending from said anchor; a deflection guide cavity in said anchor head, said deflection guide cavity having a deflection guide cavity wall, and an opening at a proximal end of said anchor head; a deflection rod having a distal portion secured within the deflection guide cavity and a proximal portion extending out of the opening of the deflection guide cavity; wherein the spine implant is configured such that, in the absence of a load applied to the proximal portion of the deflection rod, the deflection rod is aligned with the longitudinal axis of the anchor; wherein the spine implant is configured such that a load applied to the proximal portion of the deflection rod causes resilient deflection of the proximal portion of the deflection rod away from alignment with the longitudinal axis of the bone anchor; and wherein resilient deflection of the proximal portion of the deflection rod is limited by contact between the proximal portion of the deflection rod and the deflection guide cavity wall.