THIS INVENTION IS ABOUT A SYSTEM WHICH CAN BE USED IN CORRECTION AND LENGTHENING OF THE SPINE IN CASES OF SPINAL DEFORMITIES THIS CAN BE DONE IN AN EASY, GRADUAL, CONTROLLED AND ACCURATE WAY. IT IS COMPOSED OF 2 RODS EACH HAS A SMOOTH PART AND A THREADED PART, THE LATTER IS INTRODUCED IN EACH SIDE OF A THREADED HOLLOW OF THE MIDDLE CONNECTOR.THE DESIGN AND DIRECTION OF THE THREADS IN THE RODS AND CONNECTOR ALLOWS (AFTER FIXATION OF THE ROD TO THE VERTEBRAE THROUGH HOOKS AND SCREWS) WITH THE ROTATION OF THE CONNECTOR AROUND ITS LONGITUDINAL AXIS IN A CERTAIN DIRECTION, IT ALLOWS THE TWO RODS TO MOVE AWAY FROM EACH OTHER EQUALLY AND PROPORTIONATE TO THE AMOUNT OF ROTATION AND THE DISTANCE BETWEEN THE THREADS.THIS SYSTEM IS USED IN CORRECTION OF SPINAL DEFORMITIES AND ALL ITS ADVANTAGES APPEAR IN THE SERIAL CORRECTION AND LENGTHENING OF SPINAL DEFORMITY CASES IN CHILDREN DURING GROWTH PERIODS .