A medical apparatus for parallel alignment of at least two medical instruments for holding and manipulating a surgical fastening element is described. The fastening element includes a fastening part and a holding part for a connection element, the holding part being movably mounted relative to the fastening part in a mounting position. The medical instruments have a distal end couplable to the fastening element. The apparatus includes at least two coupling devices, each defining a coupling longitudinal axis, for temporary coupling with proximal ends of the at least two medical instruments, wherein the apparatus comprises a frame, wherein the coupling longitudinal axes of the at least two coupling devices are alignable parallel to one another. Improved sets of medical instruments and improved spine stabilization systems are also described.