Screw system (100) for transiliac fixation, or application in other skeletal areas, includes cannulated bone screw (10) preferably capable of spanning iliac crests (9) of a patient, having elongate, hollow body (11) with first opening (13) on a first end of the body (11) and second opening (14) on an opposing, second end of the body (11); tip (20) on the first end of the body (11, 13), which preferably is a thread-cutting tip; head (30) about the second end of the body (11, 14), which can be engaged with surgical tool (80, 83); and threads (16) on at least part of the body between the first end (11, 13) and second end (11, 14); locknut (40) with threads (46) for interference fitting corresponding generally to the threads (16); and preferably washer (50). Major-minor, pitch-diameter, locking interference fitting can be provided. Associated kit (1000) includes at least one screw system (100); guidewire (60), essentially as long as or longer than the elongate hollow body (11) of the screw (10), and over which the screw (10) can pass, beneficially being rigid with drill bit tip (61); preferably, cannulated starter drill (70) and/or a tool set (80, 83, 84) to engage the head (30) of the screw (10) for twisting the screw (10) so that it can thread through bone (9) and/or engage the nut (40) so that it can be tightened onto the first end (11, 13) of the screw (10).