Abstract: An osteosynthetic screw fastener and method of using such fastener is disclosed. When threaded onto an end of a bone screw for securing the screw to fractured bone, the fastener has a bone contacting surface that is alignable, independently of the orientation of the screw shaft, with an orientation of the bone surface adjacent to where the screw shaft exits the bone. The independent alignment of the fastener with the bone surface is due to a ball and socket configuration wherein the ball portion includes a spherical threaded nut and the socket is a cavity within the fastener for retaining the spherical nut. Accordingly, the fastener has an access to a threaded bore of the spherical nut so that the screw shaft can be threaded into the bore and secure the fastener against the bone. Additionally, the fastener's bone contacting surface is relatively large with projections thereon that secure the fastener in a desired orientation on the bone and thereby inhibit the fastener from shifting.