Variable angle screw for spinal implant system

摘要

A variable angle bone screw system for use in a spinal implant system to connect a vertebral fixation element to a spinal rod extending adjacent the vertebral column in a patient. The system includes an eyebolt having a threaded stem, a washer receivable over the stem of the eyebolt, a bone screw including a yoked head to permit top loading of the stem of the eyebolt, and a nut engaging the threaded stem of the eyebolt and cooperating with the eyebolt to clamp the bone screw and washer therebetween. The bone screw head and the washer include interdigitating locking means for restraining the pivoting of the screw about the axis of the eyebolt threaded stem but permitting interlocking in variable angular orientations.