A minimally invasive system for dynamic correction of a spinal deformity in patients includes: a flat ligament made of synthetic material, a plurality of staples intended to be anchored on a respective vertebral body of the patient to hold the ligament against each vertebral body, and a device for mechanically tensioning the ligament. Furthermore, the device for mechanically tensioning the ligament includes a tubular rod for allowing the ligament and at least one pin capable of penetrating the vertebral body so as to prevent slippage of the distal end of the rod on the vertebral body to move between a distal end and a proximal end of the rod, leading, at the distal of the rod, into a notch suitable for the ligament to pass through, and a torque wrench arranged at the proximal end of the rod, the torque wrench including a spindle that is perpendicular to the rod and has a slit through which the ligament passes, the spindle of the wrench being suitable for being rotated so as to adjust the mechanical tension of the ligament.
