Facet screws comprise a lower portion have lower threads that have a constant outer or major diameter. The lower portion of the facet screws can also have a tapered or conical shape in a direction toward the lower end, and relative to a longitudinal axis, of the facet screw. Therefore, the lower threads closest to the lower end have a greater surface area for engaging the bone of a patient as compared to the lower threads furthest away from the lower end, i.e., closest to the top of the lower threads. One or more of the lower threads also can include certain dimensions and shapes that facilitate insertion and retention of the facet screws in the bone of a patient.
