A bone plate locking system including a threaded screw body having a proximal end and a distal end and a plate with a through-hole. The proximal end includes a head. The head includes an upper portion, a groove adjacent the upper portion and a lower portion adjacent the groove, wherein a center-axis of the groove is off-axis to a center- axis of the threaded screw body. A locking ring configured to reside within the groove of the head. The through-hole includes an upper portion, a groove adjacent the upper portion and a lower portion adjacent the groove. The head is receivable in the through- hole. The locking ring is rotatably positioned around the groove of the head such that in an unlocked position the locking ring is outside the groove of the through-hole and in a locked position the locking ring is at least partially within the groove of the through-hole.