Vertebral osteosynthesis equipment

1. A vertebral osteosynthesis equipment, wherein the equipment comprises:

at least one connecting bar having a length such that it is capable to span several vertebrae to be treated, having a general longitudinal direction;

at least one flexible ligament adapted to be engaged onto a vertebra to be treated, and

at least one assembly for connecting the ligament to the connecting bar, comprising:

a connecting part having a curved portion defining an engagement conduit for engagement of the connecting bar said curved portion partly surrounds the connecting bar when the latter is placed in the engagement conduit; the connecting part further includes a central conduit and two lateral conduits each located on one side of the central conduit, in locations distant from each other, each said lateral conduit is configured for holding a strand of the ligament and each said lateral conduit is defined between the central conduit and a radially external wall of the connecting part, said external wall having an inner tilted portion which is tilted outwardly with respect to an axis of said central conduit;

a nut having an inner threaded wall;

a tightening part having a threaded pin configured for engaging said threaded wall of said nut through said central conduit, and a base extending in a plane transversely to an axis of the threaded pin, said base being configured for tightening the connecting bar in the engagement conduit; and

a pressing ring mounted on said nut and being configured to engage said tilted portion of each of said lateral conduits;

wherein the central conduit is configured for blocking the tightening part in rotation relatively to the central conduit;

wherein said tightening part and said nut are configured such that when the nut is screwed relative to the threaded pin through the central conduit said base engages the connecting bar when the connecting bar is disposed inside said engagement conduit; and

the pressing ring urges the strand of the ligament towards the tilted wall, securing the strand relatively to the connecting part.

2. The vertebral osteosynthesis equipment according to claim 1 , wherein the lateral conduits are diametrically opposite to each other, while being aligned along a direction parallel to the axis of the engagement conduit for engaging the connecting bar.

3. The vertebral osteosynthesis equipment according to claim 1 , wherein body of the connecting part comprises, in each lateral conduit, at least one anti-return protrusion forming a pronounced edge, this anti-return protrusion allowing sliding of a strand of the ligament in this conduit in the distal-proximal direction, with friction, and opposing, by penetration of said edge into the material of the ligament, the sliding of the strand in the opposite direction.

4. The vertebral osteosynthesis equipment according to claim 1 , wherein said base of the tightening part extends, in a projection along the axis of the screwing of the nut on the threaded pin, over about one quarter of the diameter of the engagement conduit for engaging the connecting bar.

5. The vertebral osteosynthesis equipment according to claim 1 , wherein said base comprises a rounded machined area at its area intended to come into contact with the connecting bar.

6. The vertebral osteosynthesis equipment according to claim 1 , wherein said central conduit includes a flat made on an inner surface of the central conduit and the threaded pin includes a corresponding flat configured to block the rotation of the tightening part with respect to the central conduit.

7. The vertebral osteosynthesis equipment according to claim 1 , wherein:

each aforementioned tilted wall is laterally bordered by two walls perpendicular to it, and

the pressing ring has two radial extensions, one of which is capable to be engaged into the proximal portion of a lateral conduit in which are found said tilted wall and said perpendicular walls, and the other one of which is capable to be engaged into the proximal portion of the other lateral conduit in which are found said tilted wall and said perpendicular walls.