Orthopedic surgical method, and structure for securing a bone screw to a bone

A method for securing a bone screw to a bone in a surgical procedure comprising:

• forming a pilot hole comprising a plurality of lobes into a bone with an effector coupled to a machining element and a drive device of a surgical robot, wherein each lobe of the plurality of lobes projects radially outward from a center of the pilot hole and the pilot hole comprises curvilinear concave vertices formed between each lobe of the plurality of lobes providing purchase areas for a helical thread of a surgical screw, wherein the plurality of lobes are sized and shaped to provide an open space between a major thread diameter of a surgical screw and a most radially outward portion of a respective end of each lobe;
• driving the surgical screw into the pilot hole, wherein the surgical screw comprises a cylindrical shank section, the shank section having at least one helical thread for engaging bone material, the at least one helical thread having the major thread diameter that is the diameter of an imaginary coaxial cylinder that just touches the crest of the at least one helical thread and a minor diameter which is the diameter of an imaginary cylinder that just touches the root of the at least one helical thread.