DEFORMABLE THREADED LOCKING STRUCTURES

A bone fixation system includes a plate body that defines an interior surface that defines at least one hole defining a central axis. The internal surface defines plate threads within the hole. The system includes a bone screw having a shaft extending from head along a central axis, wherein the head has an exterior surface that defines threads that are configured to threadedly engage the plate threads. The plate threads and head threads each have a cross-sectional profile in a respective reference plane extending along the respective central axis. The cross-sectional profiles each comprise roots, crests, and flanks extending therebetween. The roots, crests, and flanks collectively deviate from a reference cross-sectional profile that is V-shaped in the respective reference plane and defines crest reference points at apices at a first side thereof and root reference points at apices at a second side thereof opposite the first side. Such deviation causes a thread height measured from the crests to the roots to be less than a reference height measured from the crest reference points to the root reference points, such that a ratio of the thread height of the head threads to the reference height of the head threads is from 0.50:1 to 0.80:1, and a ratio of the thread height of the plate threads to the reference height of the plate threads is from 0.50:1 to 1.00:1.