Assemblies and methods for fixation of bone or bone fragments using an orthopedic plate having a slot that causes the bone or bone fragments to compress as a screw is inserted into the slot and rotated therein. By anchoring the orthopedic plate to a first bone or bone fragment and rotating the screw into the second bone or bone fragment at an angle that may be up to approximately fifteen degrees from perpendicular to the top surface of the orthopedic plate, the screw head causes the orthopedic plate to traverse away from the first screw thereby causing the first bone or bone fragment to be drawn toward and/or compress with the second bone or bone fragment.