A bone fixation element comprises a shaft extending longitudinally from a proximal end to a distal end and a head connected to the proximal end of the shaft. The head includes a radially outer abutting structure deformable to lockingly engage an inner wall of an opening through a bone plate. Deformation of the abutting structure permits the head to lock the bone fixation element within the opening at any user-selected angle with respect to a central axis of the opening within a permitted range of angulation.
