Patent ID: 7955364

Claim:
A bone fixation assembly comprising: a unitary bone fastener comprising a shaft for engaging a bone, the shaft defining a longitudinal first axis; a head extending from the shaft; and a plurality of external thread windings formed on a substantially spherical outer surface of the head, the external thread windings circumferentially interrupted by at least one slot defined on the outer surface, the slot inclined at an angle relative to the first axis and relative to the thread windings; and a fixation member comprising at least one aperture having a second axis, the aperture comprising internal thread windings formed on a substantially spherical portion of the aperture for threadably engaging the had of the bone fastener at a variable angle relative to the second axis, the at least one slot shaped and sized for guiding the fastener for controlled angled threading within the aperture without damaging the internal thread windings of the aperture.