Instrumental (1) for connecting vertebral bodies with a screw (10) screwable to a pedicle, the screw comprising a screw head (12) and an axis (14), a support (2) polyaxially connectable to the screw (10) for the coupling to a support system (100) with a bushing-shaped tulip (20) and with a first insertion opening (21) to insert the screw head (12) according to an insertion direction (E) and a tool ( 40), characterized in that the support (2) comprises a seat (30) in the inner area (22) of the tulip (20), the seat (30) comprising a receiving area (32) for receiving the screw head (12) in a first end zone (31a) oriented towards the first insertion opening (21a) and a coupling area (35) attachable with the tool (40) in a second end zone (31b) opposite the zone of reception (32), and the seat being movable between a release position (23a), reachable to the insert ar the screw head (12), and a locking position (23b), attainable by moving the screw head (12) from the release position (23a) according to the direction opposite to the insertion direction (E), in that the screw head (12) received in the reception area (32) in the locked position (23b) is not separable from the reception area (32), the seat (30) being fixed in a release position (23a) that allows the release of the screw head (12) from the reception area (32) by means of the tool (40) coupled to the coupling area (35).Instrumental (1) para conectar cuerpos vertebrales con un tornillo (10) atornillable a un pedículo, comprendiendo el tornillo una cabeza de tornillo (12) y un eje (14), un soporte (2) conectable poliaxialmente al tornillo (10) para el acoplamiento a un sistema de apoyo (100) con una tulipa (20) con forma de casquillo y con una primera abertura de inserción (21) para insertar la cabeza de tornillo (12) según una dirección de inserción (E) y una herramienta (40), caracterizado por que el soporte (2) comprende un asiento (30) en la zona interior (22) de la tulipa (20), el asiento (30) comprendiendo
