Lumbosacral osteosynthesis instrumentation for the correction of spondylolisthesis by posterior route, and instrumentation screws.

摘要

This instrumentation comprises for each lumbar vertebra (L5), two pedicle screws (1) with double thread (9, 11), one of which (9) corresponds to the zone of penetration of the screw into the pedicle, two rods (2) with asperities, respectively associated with a pedicle screw and secured therewith by connecting elements (3) equipped with rod locking members; each connecting element (3) is a single piece and the thread (9) corresponding to the zone of penetration of the screw into the pedicle ends on an annular shoulder (16) supporting the connecting element, separated by a part smooth (15) of the thread (11) outside the zone of penetration into the pedicle; this instrumentation allows both to bring the slipped vertebra backwards and to rotate it in the desired direction of rotation, the derotation action exerted being able to be done slowly and by controlling the movement, so that the surgeon thus obtains overall, in the two movements, excellent precision in the repositioning of the vertebra in relation to the neighboring vertebrae.