Osteosynthesis system having a plate

The invention relates to an osteosynthesis system (S), for reducing a distal fracture (F) of an elongate bone, and to the corresponding reduction method. The system includes a plate, provided with an epiphyseal portion comprising a substantially triangular recess and a diaphyseal portion including an oblong opening, and a removable adjustment part (9), a proximal portion of which is wider than the oblong hole and a distal portion of which is of a length L' that is greater than the length L of the recess, said adjustment part having an opening (17) suitable for placing a screw (18) for transversely positioning the plate in relation to the bone.