A system for reducing a distal fracture of a long bone, between a distal fractured part of the bone and a proximal part, comprising: an osteosynthesis plate having a widened, pallet shaped epiphyseal part, provided with first fixing holes for first anchoring screws, and an elongate diaphyseal part, provided with second fixing holes for second anchoring screws, said plate having an articulation between the epiphyseal part and the diaphyseal part, in the plane of said diaphyseal part, between two defined angle values with respect to a central alignment position; and a third anchoring screw, the epiphyseal part comprising on one side a first fixing portion forming a distal widened end thereof provided with said first fixing holes on the distal part of the fractured bone, and on the other side a second fixing portion forming a narrowed proximal end thereof, characterized in that said narrowed proximal end is provided with a first slot for fixing on the proximal part of the bone adapted to receive the third anchoring screw, in order to fix the epiphyseal part to each of the distal and proximal parts of the fractured bone so that the epiphyseal part is rigidly fixed to the bone, wherein the first slot is such that the distal and proximal parts of the fractured bone are movable relative to each other prior to insertion of the third anchoring screw into the distal part and immovable relative to each other after insertion of the third anchoring screw into the distal part, and in that the narrowed end of the epiphyseal part further comprises a blocking screw and a fixing screw, the blocking screw defining an axis of rotation between the epiphyseal and diaphyseal parts and adapted for locking the epiphyseal part to the diaphyseal part, the fixing screw being arranged for joining the epiphyseal part to the diaphyseal part through a second slot provided in the diaphyseal part. an osteosynthesis plate having a widened, pallet shaped epiphyseal part, provided with first fixing holes for first anchoring screws, and an elongate diaphyseal part, provided with second fixing holes for second anchoring screws, said plate having an articulation between the epiphyseal part and the diaphyseal part, in the plane of said diaphyseal part, between two defined angle values with respect to a central alignment position; and a third anchoring screw, the epiphyseal part comprising on one side a first fixing portion forming a distal widened end thereof provided with said first fixing holes on the distal part of the fractured bone, and on the other side a second fixing portion forming a narrowed proximal end thereof, characterized in that said narrowed proximal end is provided with a first slot for fixing on the proximal part of the bone adapted to receive the third anchoring screw, in order to fix the epiphyseal part to each of the distal and proximal parts of the fractured bone so that the epiphyseal part is rigidly fixed to the bone, wherein the first slot is such that the distal and proximal parts of the fractured bone are movable relative to each other prior to insertion of the third anchoring screw into the distal part and immovable relative to each other after insertion of the third anchoring screw into the distal part, and in that the narrowed end of the epiphyseal part further comprises a blocking screw and a fixing screw, the blocking screw defining an axis of rotation between the epiphyseal and diaphyseal parts and adapted for locking the epiphyseal part to the diaphyseal part, the fixing screw being arranged for joining the epiphyseal part to the diaphyseal part through a second slot provided in the diaphyseal part.