Minimally invasive expanding spacer and method

Abstract

A minimally invasive spacer for positioning between vertebral members. The spacer is adjustable between a first orientation having a reduced size to facilitate insertion between the vertebral members. A second orientation has an enlarged size for contacting the vertebral members. The spacer includes linkages that are attached to a pair of plates. A pull arm is operatively connected to the linkages for adjusting the spacer from the first orientation to the second orientation. A indicator gauge indicates the height of the spacer.

1 - 20 . (canceled) 
     
     
         21 . A method of spacing vertebral members comprising the steps of:
 inserting a spacer in a first orientation with a first height and a first angle between the vertebral members;   applying an axial force to a pull arm and moving an indicator gauge from a first position to a second position; and   pivoting linkages attached to the pull arm and increasing the spacer to a second height larger than the first height, and a second angle greater than the first angle.   
     
     
         22 . The method of  claim 21 , wherein the step of pivoting the linkages comprises moving the linkages from a first link angle to a second larger link angle. 
     
     
         23 . The method of  claim 22 , wherein the step of pivoting the linkages causes a plate to move outward from a centerline of the spacer to increase the spacer from the first height to the second height and from the first angle to the second angle. 
     
     
         24 . The method of  claim 21 , wherein the step of applying the axial force to the pull arm comprises rotating a handle operatively connected to the pull arm. 
     
     
         25 . A method of spacing vertebral members comprising the steps of:
 orienting a spacer in a first orientation with a first marking on a handle aligned with an indicator;   inserting a spacer in the first orientation between the vertebral members, the spacer having a first height;   rotating the handle and aligning a second marking on the handle with the indicator and causing linkages operatively attached to the handle to move thereby increasing the spacer to a second height larger than the first height.   
     
     
         26 . The method of  claim 25 , wherein the step of rotating the handle and aligning the second marking on the handle with the indicator further causes the spacer to form a second angular position that is different than a first angular position when the spacer is in the first orientation.