Variable angle spinal screw.

摘要

A spinal fastening apparatus for use in spinal fixation systems, comprising a bone screw, a collar and a locking pin. The bone screw has a threaded shaft portion with a generally longitudinal axis and a head portion having an eyelet with a central bore. The collar is generally U-shaped with a transverse axis and a slot adapted for placement over the eyelet portion of the screw. The elongated locking pin has an outer surface with gripping means on at least a portion of the outer surface and is sized and shaped to be slidably inserted through the eyelet. Surface portions of the collar and eyelet each include means for engaging the gripping means of the pin when the pin is inserted through the eyelet bore and the eyelet occupies the slot of the collar. The collar is capable of pivoting in relation to the eyelet to adjust for angulation between the longitudinal axis of the threaded shaft and the transverse axis of the collar and being locked into a selected angled position.