Screw placement guide

Abstract

A screw placement guide tool for use in minimally invasive surgery has a proximal handle portion, an extension member extending distally from the handle portion, and an alignment element connected transversely to a distal portion of the extension member and having a screw placement guide located thereon. In this aspect of the invention, the tool is configured so that a surgeon may operate the tool using the handle portion external to a patient's body to align the alignment element with implanted screws so that the screw placement guide indicates a desired position for implantation of an additional screw. Systems and methods for placing a rod receiving screw are also provided.

What is claimed is:  
     
         1 . A screw placement guide tool for use in minimally invasive surgery, comprising: 
 a proximal handle portion;    an extension member extending distally from the handle portion; and    an alignment element connected transversely to a distal portion of the extension member and having a screw placement guide located thereon;    wherein the tool is configured so that a surgeon may operate the tool using the handle portion external to a patient's body to align the alignment element with implanted screws so that the screw placement guide indicates a desired position for implantation of an additional screw.    
     
     
         2 . The tool of  claim 1 , wherein the alignment element is curved to correspond to a curve of a spinal fixation rod to be implanted.  
     
     
         3 . The tool of  claim 1 , wherein the screw placement guide is a closed loop.  
     
     
         4 . The tool of  claim 1 , wherein the alignment element is elongate, has first and second opposed ends, is connected to the extension member at a first opposed end, and has the screw placement guide located on the second opposed end.  
     
     
         5 . The tool of  claim 4 , wherein a curved portion connects the extension member to the alignment element.  
     
     
         6 . A system for placing a rod receiving screw within a patient's bone, comprising: 
 a plurality of rod receiving screws, each rod receiving screw having a proximal rod receiving opening and a distal bone attachment portion;    a screw placement guide tool having an elongate alignment element including a screw placement guide located thereon, the elongate alignment element being sized to fit within the rod receiving opening of at least one of the plurality rod receiving screws when the at least one rod receiving screw is implanted and to extend so that the screw placement guide indicates a placement location for another of the plurality of rod receiving screws.    
     
     
         7 . The system of  claim 6 , wherein the plurality of rod receiving screws includes at least three rod receiving screws and the elongate alignment element is sized to fit within the rod receiving openings of at least two of the at least three rod receiving screws when the at least two rod receiving screws are implanted and to extend so that the screw placement guide indicates a placement location for a third of the at least three rod receiving screws.  
     
     
         8 . The system of  claim 6 , wherein the screw placement guide tool further includes an extension member extending proximally from the alignment element and a handle disposed on a proximal portion of the alignment element.  
     
     
         9 . The system of  claim 6 , wherein the alignment element is curved to correspond to a curve of a spinal fixation rod to be implanted.  
     
     
         10 . The system of  claim 6 , wherein the screw placement guide is a closed loop.  
     
     
         11 . The system of  claim 6 , wherein the alignment element has first and second opposed ends, is connected to the extension member at a first opposed end, and has the screw placement guide located on the second opposed end.  
     
     
         12 . The system of  claim 6 , further including a marking tool, the marking tool being guidable to a location indicated by the screw placement guide for placing an indication on a patient's bone where a screw is to be implanted.  
     
     
         13 . A method for placing a rod receiving screw for implantation in a vertebral body, comprising: 
 implanting at least one rod receiving screw into a patient's spine, each of the at least one rod receiving screws having a distal bone attachment element and a proximal rod receiving opening; and    fitting a screw placement guide tool having an elongate alignment element including a screw placement guide located thereon within the rod receiving opening of the at least one implanted rod receiving screw so that the screw placement guide indicates a placement location for another rod receiving screw.    
     
     
         14 . The method of  claim 13 , wherein at least two rod receiving screws are implanted into a patient's spine and the screw placement guide tool is fitted to the rod receiving openings of the at least two implanted rod receiving screws so that the placement guide indicates a placement location for a third rod receiving screw.  
     
     
         15 . The method of  claim 13 , wherein the screw placement guide tool further includes an extension member extending proximally from the alignment element and a handle disposed on a proximal portion of the alignment element so that a surgeon may operate the tool using the handle portion external to a patient's body to fit the alignment element within the rod receiving openings of the at least two implanted rod receiving screws.  
     
     
         16 . The method of  claim 13 , further comprising curving the alignment element to correspond to a curve of a spinal fixation rod to be implanted.  
     
     
         17 . The method of  claim 13 , wherein the alignment element has first and second opposed ends, is connected to the extension member at a first opposed end, and has the screw placement guide located on the second opposed end.  
     
     
         18 . The method of  claim 13 , further comprising: 
 guiding a marking tool to a location indicated by the screw placement guide; and    placing an indication on a patient's bone where a screw is to be implanted using the marking tool.