The present disclosure relates to a bone fixation system for orthopaedic surgery. In one form, the system comprises a screw and a plate, the plate comprising at least one through opening, the through opening comprising a screw inlet, and a through bore which tapers inwardly as it extends through the plate from the screw inlet, the plate further comprising a plurality of splines which further define the through opening by projecting into the through bore, each spline extending longitudinally through the through opening, and comprising a top land which extends from the screw inlet and along the spline, and wherein in use, at least a portion of a head of the screw will engage with the top lands of the splines. A plate for a bone fixation system is also disclosed.