The invention relates to threaded joints for supporting and stabilizing a rear fracture of the pelvic ring or for stabilizing and stiffening the sacroiliac joint, either with a threaded bar in connection with threaded nuts or a screw in connection with the sacrum. The threaded joints are characterized by secure support and stabilization of a rear fracture of the pelvic ring or by secure stabilization and stiffening of the sacroiliac joint. The threaded joint as an implant is, for this purpose, either a threaded bar in connection with threaded nuts for supporting the rear fracture of the pelvic ring or a screw in connection with the sacrum. For this purpose, there is a washer between the ilium and the threaded nut or the screw head, the side of the washer that faces the ilium being mutually oblique in at least two planes and the oblique surfaces being arranged at an angle to each other. The washer has an opening for the passage of a region of the threaded bar or of the screw, the opening being expanded toward the ilium.