Patent attributes
A modular head pedicle screw assembly has a bone screw, a tulip, a locking split ring and a saddle. The locking split ring is internal of the tulip positioned in a recess of an inner surface of the tulip. The saddle has a proximal end for engaging a rod and a distal end for receiving the bone screw. The saddle has an exterior surface positioned between the ends. The outer surface is sized to move axially inside the tulip. The saddle expands the locking split ring in an initial pre-loaded position and upon insertion of the tulip over the bone screw, the saddle moves proximally disengaging the locking split ring simultaneously causing the locking split ring to relax to an unexpanded condition while providing tactile and audible feedback to the surgeon and locking the bone screw into the tulip.
