Set suitable for use in a bone-shortening osteotomy of a predetermined distance, the set comprising: an implant with a distal segment and a proximal segment, wherein the distal segment comprises at least two distal threaded holes and wherein the proximal segment comprises at least two proximal threaded holes; a plurality of accessories wherein: each accessory is adapted for use in a bone-shortening osteotomy of one of a plurality of predetermined different distances (d), and each accessory comprises successively a first segment, a second segment and a third segment; wherein the first segment comprises first threaded holes, the third segment comprises second threaded holes, and the second segment comprises two guides which are each adapted to guide a saw blade so that the bone-shortening osteotomy of the predetermined distance (d) can be performed via the two guides; wherein the first threaded holes and the second threaded holes respectively correspond to the at least two distal threaded holes and the at least two proximal threaded holes, with an intermediate spacing between first and second threaded holes which is equal to the sum of the predetermined distance (d) and a corresponding intermediate spacing between distal and proximal threaded holes; and, wherein the first segment and the third segment have the same shape, at least at the position of the threaded holes, as respectively the distal segment and proximal segment. an implant with a distal segment and a proximal segment, wherein the distal segment comprises at least two distal threaded holes and wherein the proximal segment comprises at least two proximal threaded holes; a plurality of accessories wherein: each accessory is adapted for use in a bone-shortening osteotomy of one of a plurality of predetermined different distances (d), and each accessory comprises successively a first segment, a second segment and a third segment; wherein the first segment comprises first threaded holes, the third segment comprises second threaded holes, and the second segment comprises two guides which are each adapted to guide a saw blade so that the bone-shortening osteotomy of the predetermined distance (d) can be performed via the two guides; wherein the first threaded holes and the second threaded holes respectively correspond to the at least two distal threaded holes and the at least two proximal threaded holes, with an intermediate spacing between first and second threaded holes which is equal to the sum of the predetermined distance (d) and a corresponding intermediate spacing between distal and proximal threaded holes; and, wherein the first segment and the third segment have the same shape, at least at the position of the threaded holes, as respectively the distal segment and proximal segment. each accessory is adapted for use in a bone-shortening osteotomy of one of a plurality of predetermined different distances (d), and each accessory comprises successively a first segment, a second segment and a third segment; wherein the first segment comprises first threaded holes, the third segment comprises second threaded holes, and the second segment comprises two guides which are each adapted to guide a saw blade so that the bone-shortening osteotomy of the predetermined distance (d) can be performed via the two guides; wherein the first threaded holes and the second threaded holes respectively correspond to the at least two distal threaded holes and the at least two proximal threaded holes, with an intermediate spacing between first and second threaded holes which is equal to the sum of the predetermined distance (d) and a corresponding intermediate spacing between distal and proximal threaded holes; and, wherein the first segment and the third segment have the same shape, at least at the position of the threaded holes, as respectively the distal segment and proximal segment.