Osteosynthesis device comprising, on the one hand a plate (12) suitable to be adjusted along a bone element (10) and at least one spike (26) intended to be fixed on said bone element (10) through said plate (12) and on the other hand, a locking bushing (30) capable of receiving at least said pin (26) and allowing said plate (12) and at least said pin (26) to be joined, the locking bushing ( 30) a screwable part (32) and a displacement part (34) for screwing said screwable part through the plate (12), with said screwable part (32) and said displacement part (34) being axially separated from each other by a breakable zone (38), the screw-in part having axial cuts (44) forming grooves (50) between said axial cuts, said screw-in part (32) being able to cooperate with said plate (12) when the screw-in part is screwed through said plate to deform co ncentrically said grooves (50), and to adjust said pin (26), said breakable zone (38) being intended to be broken to release the screwable part (32) of the displacement part (34)； this osteosynthesis device being characterized in that said axial cuts (44) extend in said breakable zone (38) so that said screwable part (32) can be fragmented into independent slots (50) when the breakable zone (38) is broken from so that the relative position of said grooves (50) around at least said spike (26) can be adjusted.Dispositivo de osteosíntesis que comprende, por una parte una placa (12) apta para ser ajustada a lo largo de un elemento óseo (10) y al menos una espiga (26) destinada a ser fijada en dicho elemento óseo (10) a través de dicha placa (12) y por otra parte, un casquillo de bloqueo (30) apto para recibir al menos dicha espiga (26) y permitiendo solidarizar dicha placa (12) y al menos dicha espiga (26), presentando el casquillo de bloqueo (30) una parte atornillable (32) y una parte de desplazamiento (34) para atornillar dicha parte atornillable a través de la placa (12), con dicha parte atornillable (32) y dicha parte de desp
