Screw

Osteosynthesis screw comprising a central shaft (1), a head (2), a central part (3) provided with a thread, and a front part (4) having a tip (5), the central part (3) divided M areas on a body widening towards the head (2) and N areas (31, 33) comprising a circular cylindrical core comprising. (I) M and N are integers greater than 0 and numbers and their difference being the most equal to the value 1; (Ii) areas (32) comprising a core are widened in the direction of the head portion (2) and areas (31,33) a cylindrical circular core being arranged alternately with the other comprising a; (Iii) all zones (31,32, 33) constituting the central part (3) they are provided with a continuous thread (6); (Iv) the central part (3) is provided with a continuous thread (6) presenting a substantially constant outer diameter D; (V) M = 1 and N = 2, and (vi) the front part (4) decreases towards the tip (5) being in formaabombada, characterized in that (vii) the front part (4) tapers convexly toward the tip (5) and has a thread (8).