System for fixing an osteosynthesis material against a bone (16), this system comprising at least: - i) a screw (12) including a threaded rod (13) and a rear end (14a), and - ii) a screwdriver (1) including a handle (3) extended in a rod (5) whose front end carries a tip (7) capable of cooperating with the rear end (14a) of the screw (12), said screwdriver equipped being a guide member (4) of the screw (12), attached to the rod (5), and having a front end (4a) emerging portion of the guide member (4) ahead of the tip (7) screwdriver (1) and extending along or around a part of the screw (12) to guide in the direction of axial translation, and the guide member (4) slidably mounted on the rod (5) being, being provided locking means in at least one position of said control (4) along the rod (5), characterized in that the torn illio (12) is formed from a material comprising a polymer, the screw is inserted with possibility of free translation in the guide member and the guide member (4) is blocked by said blocking means in a position to along the rod (5) corresponding to a predefined depth of screwing of the screw (12), making said front end (4a) of the guide member (4) a cap screwdriver (1) against the surface of said osteosynthesis material when a predefined depth of screwing of the screw (12) in the bone tissue (16) is reached, causing blockage of the advance of the screwdriver (1) and then allowing the stop screw by separating the rear end (14a) of the screw (12 ) and the tip (7).Sistema de fijación de un material de osteosíntesis contra un tejido óseo (16), comprendiendo este sistema al menos: - i) un tornillo (12) que incluye un vástago roscado (13) y un extremo posterior (14a), y - ii) un destornillador (1) que incluye un mango (3) prolongado en una varilla (5) cuyo extremo anterior es portador de una punta (7) apta para cooperar con el extremo posterior (14a) del tornillo (12), estando dicho destornillador equipado con un órgano de guía (4) del tornillo (12), uni
