A screw system includes an inner member and a cannulated outer member that may be pre-assembled with an inner member driver and an outer member driver to form a surgical assembly. A method of inserting the screw system includes advancing the inner member into the bone by using the inner member driver, and advancing the outer member into the bone by using the outer member driver. The inner member acts as a guide for the outer member, and eliminates the need for a separate guide wire. The pre-assembled nature of the surgical assembly eliminates the need to sequentially remove and apply drivers and implant parts. The inner member and the outer member are configured to integrate into a substantially solid body when in a final alignment, thus forming a stronger implant than a cannulated screw.