Screw and rod fixation system

Abstract

A pedicle screw and rod fixation assembly including a pair of opposing tabs having a proximal end and a distal end, the pair of opposing tabs being coupled to one another about the distal end thereof by a screw head member, a decoupling mechanism for decoupling the pair of opposing tabs from the screw head member, a rod receiving slot between the pair of opposing tabs, and a sliding member configured for coupling to the pair of opposing tabs. The sliding member and the pair of opposing tabs are configured for allowing movement of the sliding member distally along the pair of opposing tabs and preventing movement of the sliding member proximally along the pair of opposing tabs.

It is claimed: 
     
         1 . A screw and rod fixation assembly comprising,
 a pair of opposing tabs having a proximal end and a distal end, the pair of opposing tabs being coupled to one another about the distal end thereof by a screw head member,   a rod receiving slot between the pair of opposing tabs, and   a sliding member configured for coupling to and between the pair of opposing tabs,   wherein the sliding member is configured for allowing movement of the sliding member distally along the pair of opposing tabs when the sliding member is pushed along the pair of opposing tabs by a human hand exerting a force directed towards the screw head member and preventing movement of the sliding member proximally along the pair of opposing tabs.   
     
     
         2 . The assembly according to  claim 1  wherein the screw head member is coupled with a pedicle screw. 
     
     
         3 . The assembly according to  claim 1  further comprising a pawl extending to and between a tab of the pair of opposing tabs and the sliding member. 
     
     
         4 . The assembly according to  claim 3  wherein the pawl is integral with the sliding member and slidably coupled with the tab of the pair of opposing tabs. 
     
     
         5 . The assembly according  claim 4  wherein the sliding member includes a release for selectively disengaging the pawl from a pawl receiving groove in the tab of the pair of opposing tabs. 
     
     
         6 . The assembly according to  claim 1  wherein the sliding member includes a collar having an opening for receiving the pair of opposing tabs and a set screw therethrough. 
     
     
         7 . The assembly according to  claim 6  wherein the pair of opposing tabs are received within the opening and at least one pawl is extending between the collar and a tab of the pair of opposing tabs. 
     
     
         8 . The assembly according to  claim 6  wherein the collar includes at least one protuberance extending from a lower edge thereof, the at least one protuberance being aligned with the rod receiving slot. 
     
     
         9 . The assembly according to  claim 1  further comprising a rod positioned within the rod receiving slot and between the screw head member and the sliding member, the sliding member pressing against the rod. 
     
     
         10 . The assembly according to  claim 9  further comprising a set screw threaded between the pair of opposing tabs and proximal to the rod, the set screw pressing the rod against a rod seat within the screw head member. 
     
     
         11 . The assembly according to  claim 1  wherein the sliding member includes a flexible portion. 
     
     
         12 . A method for reduction of a rod into the screw head member of  claim 1  comprising,
 inserting the rod into the rod receiving slot, 
 coupling the sliding member to the pair of opposing tabs, and 
 pushing the sliding member along the pair of opposing tabs toward the distal end thereof thereby directing the rod into a rod seat of the screw head member. 
 
     
     
         13 . An assembly comprising.
 extension tabs detachably coupled to a screw head,   a rod receiving slot formed between the extension tabs,   a collar configured for being pushed along the extension tabs toward the screw head with a hand exerting a force directed towards the screw head, and   a ratchet mechanism configured for preventing movement in a predetermined direction between the collar and the extension tabs.   
     
     
         14 . The assembly according to  claim 13  wherein the ratchet mechanism includes at least one pawl. 
     
     
         15 . The assembly according to  claim 14  wherein the at least one pawl is biased toward a central axis of the collar. 
     
     
         16 . The assembly according to  claim 13  wherein the ratchet mechanism is coupled to and between the collar and the extension tabs. 
     
     
         17 . The assembly according to  claim 13  wherein the ratchet mechanism includes a first portion that is integral with the collar and a second portion that is integral with the extension tabs. 
     
     
         18 . The assembly according to  claim 17  wherein the first portion is detachably coupled with the second portion. 
     
     
         19 . The assembly according to  claim 17  wherein the first portion includes pawls and the second portion includes pawl receiving grooves. 
     
     
         20 . The assembly according to  claim 17  wherein the first portion is movable relative to the collar and the second portion is stationary relative to the extension tabs.