A spinal support rod kit for the treatment of spinal column shape deformations, comprises a first spinal support rod whose cross-section is non-circular at least at one end thereof and a second spinal support rod whose cross-section is circular along at least part of its length. A socket attached to the second support rod at one end is shaped so that the non-circular end of the first support rod can be received in the socket. The second support rod can include a mechanical locking component which can engage the non-circular end of the first support rod when it is inserted into the socket to prevent it from being withdrawn.
