Modular tulip assembly

Abstract

A modular tulip assembly has a rod receiving tulip and a saddle. The saddle is interlockingly held inside a distal portion of the tulip. The saddle has a locking projection. The tulip has a pair of grooves or recesses. The locking projection is positioned into the proximal tulip groove or recess and holds the saddle in a pre-loaded unlocked state ready to be pushed onto a head of an implanted bone screw. Upon receiving the head of the bone screw, the saddle can be moved distally relative to the tulip to a locked state by moving the locking projection distally into the distal tulip locking groove or recess.

1 .- 12 . (canceled) 
     
     
         13 . A method of assembling a tulip comprises the step of:
 providing a tulip with a pair of grooves or recesses, the pair of grooves or recesses being a proximal groove or recess and a distal locking groove or recess; and   positioning a saddle with a concave locking surface inside the tulip into a proximal groove or recess inside the tulip in a pre-loaded unlocked state to receive a head of a bone screw.   
     
     
         14 . The method of  claim 13  further comprises the step of:
 pushing the tulip with the pre-loaded unlocked saddle onto an implanted bone screw previously threaded into bone. 
 
     
     
         15 . The method of  claim 14  further comprises the step of:
 moving the saddle to a locked state by moving the locking projection from the proximal tulip groove or recess distally into the distal tulip locking groove or recess. 
 
     
     
         16 . The method of  claim 15  of moving the saddle to a locked position further includes engaging internal threads of the saddle with a threaded end of a tool, rotating the tool to move the saddle from the pre-loaded unlocked state to the locked state after attaching the implanted screw. 
     
     
         17 . The method of  claim 16  further comprises the step of:
 unlocking the locked tulip assembly by moving the saddle by moving the saddle from the locked state to the pre-loaded unlocked state. 
 
     
     
         18 . The method of  claim 17  wherein the step of unlocking the tulip assembly includes engaging threads of the saddle with the threaded end of the tool and rotationally pulling the saddle proximally relative to the tulip. 
     
     
         19 .- 30 . (canceled)