Break-off screw extensions

Abstract

The present invention provides minimally invasive devices and methods for delivering a spinal connector to one or more spinal anchor sites in a patient's spinal column. In one embodiment, a spinal implant and access device is provided that includes a U-shaped receiver member, a bone-engaging member, and an extension member. The U-shaped receiver member can have a recess formed therein that is adapted to seat a spinal connector. The bone-engaging member can extend distally from the receiver member and it can be adapted to engage bone to thereby mate the receiver member to bone. The extension member can extend proximally from the receiver member and it can include a frangible portion formed thereon that is adapted to break when a predetermined force is applied thereto thereby allowing at least a portion of the extension member to be separated from the receiver member.

1 - 21 . (canceled) 
   
   
       22 . A pedicle screw assembly comprising:
 a screw having a threaded shaft and a head;   a body coupled to the screw head and having a channel adapted to receive a spine rod therein;   at least one tab projecting upwardly from the body; and   a frangible joint joining the at least one tab to the body such that the tab is adapted to be separated from the body at the frangible joint.   
   
   
       23 . The pedicle screw assembly of  claim 22 , further comprising:
 a pair of the tabs;   a pair of the frangible joints; and   a pair of spaced arms extending upwardly from the body, the channel being defined between the spaced arms and each of the tabs being coupled to one of the arms along one of the frangible joints.   
   
   
       24 . The pedicle screw assembly of  claim 23 , wherein the pair of tabs are spaced from one another and form a pair of slots there between, each of the slots being in communication with the channel. 
   
   
       25 . The pedicle screw assembly of  claim 22 , wherein the body is a polyaxial body adapted to be positioned in a plurality of orientations relative to a longitudinal axis of the screw shaft. 
   
   
       26 . The pedicle screw assembly of  claim 22  further comprising: a set screw adapted to threadably engage the body and capture a rod in the channel. 
   
   
       27 . The pedicle screw assembly of  claim 22 , wherein the at least one tab is elongate and adapted to extend percutaneously from the body when the screw assembly is inserted into a patient's vertebrae. 
   
   
       28 . The pedicle screw assembly of  claim 22 , further comprising:
 a collar adapted to releasably mate with the at least one tab extending from the body.   
   
   
       29 . A pedicle screw assembly comprising:
 a screw having a threaded shaft and a head;   a polyaxial body coupled to the screw head being adapted to be positioned in a plurality of orientations relative to a longitudinal axis of the screw shaft;   a pair of spaced arms extending upwardly from the body, a channel being defined between the spaced arms and adapted to receive a spine rod therein;   a pair of elongate tabs each projecting upwardly from the polyaxial body and adapted to extend percutaneously from the body when the screw assembly is inserted into a patient's vertebrae;   a pair of slots formed between the pair of tabs, each of the slots being in communication with the channel;   a pair of the frangible joints each joining one of tabs to the polyaxial body such that the tab is adapted to be separated from the body at the frangible joint; and   a set screw adapted to threadably engage the body and capture the rod in the channel.   
   
   
       30 . The pedicle screw assembly of  claim 29 , further comprising:
 a collar adapted to releasably mate with the at least one tab extending from the body.   
   
   
       31 . A method of installing a spinal fixation construct onto a patient's spine, the method comprising the steps of:
 making a first incision in the patient's skin proximate selected vertebrae of the patient;   inserting first and second screw assemblies into first and second vertebra, respectively, each screw assembly having a tab extending percutaneously from the patient when the screw assembly is inserted into the associated vertebra to retract patient tissue proximate the first incision;   inserting a rod through the first incision proximate the tab of at least one of the screw assemblies;   seating the rod in a channel in each of the screw assemblies;   securing the rod in the channel of each of the screw assemblies; and   removing each of the tabs from the associated screw assembly.   
   
   
       32 . The method of  claim 31 , further comprising:
 making a second incision spaced from the first incision;   wherein the first and second screw assemblies are inserted through the first and second incisions, respectively.   
   
   
       33 . The method of  claim 31 , further comprising:
 prior to the seating and the securing steps, forming the rod into a desired configuration based on the relative positions of the tabs extending percutaneously from the first and second screw assemblies.   
   
   
       34 . The method of  claim 31 , further comprising:
 making a second incision spaced from the first incision and extending proximate the second and a third vertebra;   wherein the first and second screw assemblies are inserted through the first and second incisions, respectively, into the associated vertebrae;   inserting a third screw assembly through the second incision; and   inserting the third screw assembly into the third vertebra.   
   
   
       35 . The method of  claim 31 , further comprising:
 coupling a collar to selected screw assemblies such that a portion of each collar is positioned percutaneously.