Expandable implant for the spinal column

Expandable implant with an upper plate and a lower plate which serve for anchoring on/in the vertebral support surfaces, and at least two gears for the expansion of the implant, which are coupled to each other via toothed wheels, characterized in that each gear comprises threaded spindles and threaded sleeves, the threaded spindles are connected rigidly to the upper plate, and the threaded sleeves are mounted rotatably in the lower plate, and on one gear a drive shaft is provided, which is connected rigidly to the one threaded sleeve, wherein one of the threaded sleeves, one of the toothed wheels and the drive shaft are formed as a single piece, wherein a force acting on the drive shaft of an operating instrument can be transferred to the gear by means of the drive shaft, wherein the implant comprises means for rigidly securing, screwing or fixing the operating instrument on the implant, and wherein the drive shaft is a ring gear.