Osteosynthesis device (10), especially a Pedikel screw, with a bone anchor (14) that has a stem (16) and a head (28), especially a bone screw, and with a fork head (32) in U-shape in a side view, which has two arms (36) in a proximal terminal area (34) and is integrally configured, wherein the head (28) of the bone anchor (14) is pivotally mounted in a distal end zone (38) of the fork head (32) away from the arms (36), wherein the fork head (32) has in the distal end zone (38) a housing opening (46) limited in the direction radial by spring segments (48) for the head (28) of the bone anchor (14), wherein the spring segments (48) are radially limited on the inside by the housing opening (46), where the head ( 28) of the bone anchor (14) is inserted into the housing opening (46) from the distal end of the head of fork (32), characterized in that the spring segments (48) are radially limited on the outside by means of an annular groove, (50) arranged concentrically with respect to the housing opening (46) and forming a housing for a safety element (52 ), where the annular groove (50) is cylindrically configured, a security element (52) being provided that is arranged without possibility of loss in the annular groove (50), and where the security element (52) is provided configured as a circular ring-type locking sleeve, preferably cylindrical, and is fixed in the annular groove (50) and prevents the spring segments (48) from moving radially outward.Dispositivo de osteosíntesis (10), en especial un tornillo Pedikel, con un anclaje óseo (14) que presenta un vástago (16) y una cabeza (28), en especial un tornillo óseo, y con una cabeza de horquilla (32) en forma de U en una vista lateral, que presenta dos brazos (36) en una zona terminal proximal (34) y está configurada de forma enteriza, en donde la cabeza (28) del anclaje óseo (14) está montada de forma basculante en una zona terminal distal (38) de la cabeza de horquilla (32) alejada de los brazos (36), en donde la cabe
