The device has osseous implants (1), where each implant is implantable in a vertebral body of vertebra and includes a connection element (2). A rigid bar (3) connects the implants through the connection elements. Each connection element comprises a seat (21) for receiving a part of the bar, and an immobilization unit for immobilizing the bar. Another bar (4) has specific malleability with respect to the former bar. Each connection element comprises another seat (22) for receiving the latter bar, and immobilization units for immobilizing the latter bar in the latter seat.