The invention relates to a self-tapping and self-boring osteosynthesis screw for compressive orthopaedic surgery, characterised in that, in the bone engagement regions, at both the distal portion (A1a) and at the proximal portion (A2a), the sum of the angles defining the outer taper of the shank (f) and the taper of the crest line of the screw thread pitch (P) is higher than 45°, and in that the leading portion (i.e. the most distal one) of each thread includes a plurality of cutting edges (AR) obtained by stock removal.