Principles of lag screw technique. A, To determine best location and inclination, forceps temporarily compress fracture. B, Lag screw replaces forceps in location and position (inclination). C, Lag screw is best positioned at right angle to fracture plane. Use of bisecting angle is correct only for fractures with less than 40 degrees of inclination. If inclination is 60 degrees, fracture is displaced because of insufficient inclination of lag screw. (Redrawn after Müller ME, Allgöwer M, Schneider R, et al: Manual of internal fixation: techniques recommended by the AO-ASIF group, ed 3, Berlin, 1990, Springer-Verlag.) SEE TECHNIQUE 53.4.