A locking plate system includes a locking plate having a screw hole with an inner diameter and internal threads, and a slot formed in a top surface of the locking plate adjacent the screw hole. The system includes a screw guide having a main body including an upper end and a lower end, and an attachment flange projecting from the lower end of the main body for insertion into the slot. The screw guide includes a central opening having an inner diameter that matches the inner diameter of the screw hole. The system includes a locking screw having external threads extending along the length thereof. The external threads have an outer diameter that matches the inner diameter of the central opening of the screw guide. The locking screw is insertable into the central opening of the screw guide for being directed into the screw hole.