Vertebral osteosynthesis equipment

An equipment for a vertebral osteosynthesis comprising:

• at least one connecting bar,
• at least one flexible ligament,
• at least one connector to connect said flexible ligament to said connecting bar, the connector including:
• a first portion including a first conduit for engaging the connecting bar, a first tapped bore, and an immobilizing device connected to the first tapped bore to immobilize the connector relative to said connecting bar,
• a second portion including a second conduit to receive at least one strand of the flexible ligament, the second conduit includes an insertion opening, an outlet opening, and a tapped bore, the tapped bore is perpendicular to the second conduit,
• said second conduit being separate from the first conduit;
• a lever having an end configured to pivotably connect to the connector, the lever pivots along an axis of said first conduit, while leaving free access to the immobilizing device of the connector relative to said connecting bar and said tightening member, such that maneuvering the immobilization device means and the tightening member in order to perform this immobilization and tightening is possible when the lever is engaged with the connector, while leaving free access to the ligament, such that the latter can be stressed;
• instruments for maneuvering said immobilization device and said tightening screw when said lever is engaged with the connectors;
• a tightening member to immobilize the ligament relative to the connector;
• wherein:
• said second conduit is separated from the first conduit by a planar surface which extends from a lower edge of the insertion opening to the outlet opening;
• the tightening member is situated opposite to said planar surface;
• said insertion opening is for inserting the at least one strand of the ligament to the connector and said outlet opening is for letting the at least one strand to extend outside the connector from said second conduit;
• said second conduit is rectilinear between said insertion opening and said outlet opening,
• said tightening member is connected to the tapped bore of said second portion;
• said tightening member is a screw having a length with thread extending only over a proximal portion of the length;
• said second conduit has a transverse section adjusted to a transverse section of the at least one strand of the ligament that it is intended to receive, the transverse section has just a sufficient width to allow sliding of the at least one strand of the ligament in said second conduit, the at least one strand is in close contact with walls delimiting said second conduit.

A method for derotation of a vertebrate, i.e. pivoting of said vertebra(e) around themselves substantially along their cervico-caudal axis in order to resituate said vertebrate in anatomically normal positions, wherein the method includes the following steps:

• using an equipment for a vertebral osteosynthesis comprising:
• at least one connecting bar;
• at least one flexible ligament, at least one connector to connect said flexible ligament to said connecting bar, the connector including:
• a first portion including a first conduit for engaging the connecting bar and an immobilizing device to immobilize the connector relative to said connecting bar, and a second portion including a second conduit to receive at least one strand of the flexible ligament, the second conduit includes an insertion opening and an outlet opening;
• said second conduit being separate from the first conduit and not in communication therewith;
• said second conduit includes a tightening member to immobilize the ligament relative to the connector;
• wherein:
• said insertion opening is for inserting the at least one strand in the connector and opens on an outside of the connector, and said outlet opening is for letting the at least one strand to extend outside the connector from said second conduit and opens on the outside of the connector;
• said second conduit is rectilinear between said insertion opening and said outlet opening;
• said tightening member for immobilizing the ligament is connected to a tapped bore formed in said second portion, with an axis perpendicular to said second conduit and having an inner portion communicating with the second conduit;
• said tightening member is a screw capable of being received in said bore, having a planar and smooth inner end surface, and said second conduit has a transverse section adjusted to a transverse section of the at least one strand of the ligament that it is intended to receive, the transverse section has just a sufficient width to allow sliding of the at least one strand of the ligament in said second conduit, the at least one strand is in close contact with walls delimiting said second conduit;
• engaging the connector on a connecting bar, then connecting said bar to help the vertebrae situated on either side of the vertebra to be straightened, and engaging the ligament connected to that vertebra in said second conduit of the connector;
• engaging a lever on the connector then, releasing said tightening member such that pivoting of the connector relative to the connecting bar is possible, pivoting the connector toward the vertebra in the direction shortening the portion of the ligament extending between the vertebrae in the connector;
• in that position of the connector, stressing the ligament and tightening said tightening member;
• pivoting the connector using the lever in the opposite direction, performing pivoting of the vertebra with the connector toward a straightened position of the vertebra;
• in this straightening position thus achieved by the connector and the vertebra, maneuvering said immobilization device so as to immobilize the connector, and therefore the vertebra, in this straightening position.