Expandable implant for the spinal column

The invention relates to an expandable implant with an upper plate (12) and a lower plate (16) which serve for anchoring on/in the vertebral support surfaces, and at least two gears (21, 23; 22, 24) for the expansion of the implant, which are coupled to each other via toothed wheels (28, 29), wherein each gear (21, 23; 22, 24) comprises threaded spindles (21, 22) and threaded sleeves (23, 24), the threaded spindles (21, 22) are connected rigidly to the upper plate (12), and the threaded sleeves (23, 24) are mounted rotatably in the lower plate (16), and on one gear (22, 24) a drive shaft (30) is provided, which is connected rigidly to the one threaded sleeve (24), and wherein a force acting on the drive shaft (61) of an operating instrument (60) can be transferred to the gear (22, 24) by means of the drive shaft (30), and the implant comprises means (49) for rigidly securing, screwing or fixing the operating instrument (60) on the implant. The invention also relates to an operating instrument (60) for an implant.