An orthopedic screw and plate system in which the screw has a single male thread profile disposed on its shaft. The thread profile is uniform and unitary. The plate provides plate holes. A female thread profile is disposed on the interior of the plate holes, and extends through the thickness of the plate. The female thread profile is configured for matching threaded engagement with the male thread profile on the shaft of the screw, such that when the screw is threadably received through the plate hole and into a bone, threaded engagement between the screw and the plate locks the plate in a desired position relative to the bone. Methods of fixation are also described using the disclosed screw and plate system.