A bone plate having a plurality of openings for receiving a compression bone screw or a cortical screw. An end cap, threadably insertable in the opening and having a layer of polymeric material interposed between the end cap and the top of the head such that the compression of the polymeric material would allow slight axial movement of the screw. Alternatively, a locking ring adapted to attach to the head of the screw and having shape complimentary to the features formed on the head. The locking ring and the bone screw being assembled together and being insertable in the bone simultaneously using a dedicated instrument. Compression may be applied to a bone fracture by turning the bone screw alone after the locking ring has reached its final axial position.