Instruments and methods for reduction of vertebral bodies

Abstract

A spinal stabilization system may be formed in a patient. In some embodiments, a minimally invasive procedure may be used to form a spinal stabilization system in a patient. Bone fastener assemblies may be coupled to vertebrae. Each bone fastener assembly may include a bone fastener and a collar. The collar may be rotated and/or angulated relative to the bone fastener. Extenders may be coupled to the collar to allow for formation of the spinal stabilization system through a small skin incision. The extenders may allow for alignment of the collars to facilitate insertion of an elongated member in the collars. An elongated member may be positioned in the collars and a closure member may be used to secure the elongated member to the collars. A reducer may be used to achieve reduction of one or more vertebral bodies coupled to a spinal stabilization system.

1 . A system for reduction of one or more vertebral bodies of a human spine, comprising: 
 a collar configured to couple to a human vertebra;    an extender configured to couple to the collar;    an elongated member configured to be positioned in the collar; and    a reducer configured to couple to the elongated member and the extender, wherein the reducer seats the elongated member in the collar.    
   
   
       2 . The system of  claim 1 , further comprising a closure member configured to be coupled to the collar when the reducer seats the elongated member in the collar.  
   
   
       3 . The system of  claim 1 , further comprising a driver configured to secure a closure member to the collar.  
   
   
       4 . The system of  claim 1 , wherein the collar is a portion of a bone fastener assembly.  
   
   
       5 . The system of  claim 1 , wherein the reducer comprises at least one boss configured to couple to a recess in the extender, and wherein the reducer comprises a base configured to couple to a sleeve positioned in working relation to the extender.  
   
   
       6 . The system of  claim 1 , further comprising an extender configured to couple to the collar, wherein the reducer comprises a hollow shaft configured to surround a portion of the extender and contact the elongated member, wherein the reducer comprises a ring configured to engage a flange of the extender, and wherein the reducer comprises a rotator, wherein turning the rotator in a first direction moves the ring away from the elongated member and seats the elongated member in the collar.  
   
   
       7 . A system for reduction of one or more vertebral bodies of a human spine, comprising: 
 a collar configured to couple to a human vertebra;    an extender configured to couple to the collar;    an elongated member configured to be positioned in the collar;    a sleeve configured to surround a portion of the extender and couple to the elongated member; and    a reducer configured to couple to the extender and to the sleeve, wherein rotation of the reducer relative to the sleeve is configured to seat the elongated member in the collar.    
   
   
       8 . The system of  claim 7 , further comprising a closure member configured to couple the collar to secure the elongated member relative to the collar.  
   
   
       9 . The system of  claim 7 , further comprising a driver configured couple to a closure member, wherein the driver is configured to be positioned in the extender when the reducer is in use to seat the elongated member in the collar.  
   
   
       10 . The system of  claim 7 , wherein the reducer comprises bosses that engage recesses in the extender.  
   
   
       11 . A reducer comprising: 
 a grip;    a base coupled to the grip, wherein the base is configured to couple to a sleeve in contact with an elongated member;    an arm coupled to the base, wherein the arm is configured to couple to an extender attached to a collar of a bone fastener assembly; and    wherein rotation of the grip when the arm is coupled to the extender raises the extender relative to the sleeve.    
   
   
       12 . The reducer of  claim 11 , wherein the arm comprises a boss configured to couple to a recess in the extender.  
   
   
       13 . The reducer of  claim 11 , further comprising a locking mechanism to inhibit movement of the arm.  
   
   
       14 . A device for reduction of a vertebral body of a human spine, comprising: 
 a tube configured to accept an extender, wherein a distal end of the extender is coupled to a collar of a spinal stabilization system during use, wherein the spinal stabilization system is coupled to the vertebral body during use, and wherein a distal portion of the tube is configured to engage an elongated member of the spinal stabilization system proximate the collar during use; and    a movement mechanism coupled to a proximal portion of the tube, wherein a portion of the movement mechanism is configured to couple to a proximal end of the extender above a skin surface during use, and wherein the device is configured such that engaging the movement mechanism during use translates the vertebral body toward the proximal portion of the tube to seat the elongated member in the collar.    
   
   
       15 . The device of  claim 14 , further comprising a release mechanism coupled to the movement mechanism, wherein the release mechanism is configured such that engaging the release mechanism releases the extender from the movement mechanism.  
   
   
       16 . A method of reducing one or more vertebral bodies of a human spine, comprising: 
 attaching a first collar to a first vertebral body;    attaching a second collar to a second vertebral body;    coupling the first collar to the second collar; and    translating the first vertebral body relative to the second vertebral body from above a surface of the skin.    
   
   
       17 . The method of  claim 16 , wherein coupling the first collar to the second collar comprises coupling an elongated member to the first collar and to the second collar, and further comprising coupling a reducer to the elongated member proximate the first collar and using the reducer to translate the first vertebral body toward a proximal end of the reducer.  
   
   
       18 . The method of  claim 16 , further comprising securing a position of the first vertebral body relative to a position of the second vertebral body following translation of the first vertebral body.  
   
   
       19 . The method of  claim 16 , wherein translating the first vertebral body relative to the second vertebral body comprises translating the first vertebral body by at least 5 mm.  
   
   
       20 . The method of  claim 16 , further attaching a third collar to a third vertebral body, and coupling the third collar to the first collar or the second collar.  
   
   
       21 . The method of  claim 16 , further comprising attaching a third collar to a third vertebral body, and coupling the third collar to the first collar and the second collar.  
   
   
       22 . A method of reducing one or more vertebral bodies of a human spine, comprising: 
 coupling a reducer to a collar of a first bone fastener assembly secured to a first vertebra;    coupling the reducer to an elongated member that is secured to a second vertebra; and    activating the reducer to seat the elongated member in the collar of the first bone fastener assembly.    
   
   
       23 . The method of  claim 22 , wherein coupling the reducer to the collar comprises attaching the reducer to recesses in an extender coupled to the extender.  
   
   
       24 . The method of  claim 22 , wherein coupling the reducer to the elongated member comprises placing a sleeve over an extender, wherein the extender is coupled to the collar, coupling the reducer to the extender, and placing a base of the reducer on a handle of the sleeve.  
   
   
       25 . The method of  claim 22 , further comprising coupling a closure member to the collar when the elongated member is seated in the collar to secure the elongated member to the collar.