Abstract: The subject of the invention is a surgical strut for treatment of the back-bone.The strut has a rod having a round cross section provided at one end with a number of through holes disposed perpendicularly to the rod axis. The axes of neighboring holes form an angle of 90.degree.. Said holes are aimed at fitting a pin fixing the position of the hook, mostly the pectoral one, mounted on the rod. Said hook is provided with a round hole the wall whereof is from the side of the front face provided with four recesses disposed on the periphery every 90.degree., constituting the seats for the pin.In order to maintain a suitable elasticity the rods of the struts having the lengths smaller than 250 mm have a differentiated diameter the dimension whereof in relation to the rod length constitutes a ratio of 1:20 through 1:35. The hook co-operating with this section of the rod, mostly the lumbar hook, is provided with a blind hole wherein the rod end is supported.