Minimally invasive spinal fusion system and method

Abstract

Disclosed herein are minimally invasive systems and method for stabilizing the spine, while preserving a degree of spinal flexion and extension of the spine at the level of the stabilized vertebrae postoperatively. The systems and methods can include an expandable anchor and rod that span an intervertebral disc. The anchor can have interstices, and ends in two adjacent vertebral bodies. The system can also include a volume of bone cement media.

1 . (canceled) 
     
     
         2 . A method for stabilizing the spine, comprising:
 inserting an anchor having interstices into the interior of a first vertebral body, through an intervertebral disc, and into the interior of a second vertebral body adjacent the first vertebral body such that a distal end of the anchor is within the interior of the second vertebral body, a proximal end of the anchor is within the interior of the first vertebral body, and a central portion of the anchor spans the intervertebral disc;   expanding the distal end of the anchor within the interior of the second vertebral body;   expanding the proximal end of the anchor within the interior of the first vertebral body;   flowing a first volume of media into the distal end of the anchor within the interior of the second vertebral body, wherein the media flows through the interstices of the anchor outside the anchor and into the interior of the second vertebral body;   inserting a rod into the interior of the first vertebral body, through the intervertebral disc, and into the interior of the second vertebral body, such that a distal portion of the rod is positioned within the interior of the second vertebral body, the proximal portion of the rod is positioned within the interior of the first vertebral body, and a central portion of the rod spans the intervertebral disc, wherein the rod resides at least partially within an interior of the anchor.   
     
     
         3 . The method of  claim 2 , wherein substantially no media flows within the intervertebral disc. 
     
     
         4 . The method of  claim 2 , wherein the method does not involve a discectomy procedure. 
     
     
         5 . The method of  claim 2 , wherein the media comprises PMMA. 
     
     
         6 . The method of  claim 2 , wherein the volume of media is between about 1 cc and about 5 cc. 
     
     
         7 . The method of  claim 2 , wherein the rod comprises a carbon fiber material. 
     
     
         8 . The method of  claim 7 , wherein the carbon fiber material comprises PEEK. 
     
     
         9 . The method of  claim 2 , wherein expanding the distal end of the anchor within the interior of the second vertebral body and expanding the proximal end of the anchor within the interior of the first vertebral body comprises expanding a balloon. 
     
     
         10 . The method of  claim 2 , wherein the inserting the anchor step comprises inserting the anchor carried proximate the distal end of a balloon catheter. 
     
     
         11 . The method of  claim 2 , wherein a central portion of the anchor is not expanded, and the distal and proximal expanded portions of the anchor have a maximal expanded diameter that is at least 2× the unexpanded diameter of the central portion of the anchor. 
     
     
         12 . The method of  claim 2 , wherein the anchor comprises a shape memory material. 
     
     
         13 . The method of  claim 2 , wherein the anchor is inserted in a compressed substantially tubular configuration. 
     
     
         14 . The method of  claim 2 , wherein following insertion of the rod the volume of media hardens, fixing the distal end of the anchor and the distal portion of the rod in place. 
     
     
         15 . The method of  claim 2 , further comprising flowing an additional volume of media into the proximal end of the anchor with the interior of the first vertebral body, the flowing occurring after inserting the rod, such that the proximal portion of the rod is in contact with the additional volume of media after flowing the additional volume. 
     
     
         16 . A system for stabilizing the spine, comprising:
 an anchor having a proximal end, a distal end, and a central portion, the anchor having a compressed configuration and an expanded configuration, wherein in the expanded configuration the proximal end and the distal end of the anchor have maximal expanded diameters at their widest portions of greater than the diameter of the central portion of the anchor, wherein the anchor is sized and configured such that the proximal end of the anchor can reside within the interior of a first vertebrae, the distal end of the anchor can reside within the interior of a second vertebrae adjacent the first vertebrae, and the central portion of the anchor spans an intervertebral disc between the first vertebrae and the second vertebrae, and wherein the distal end can be expanded without expanding the proximal end and the central portion and the proximal end can be expanded without expanding distal end and the central portion, the anchor being defined by an expandable frame forming an interior extending from the proximal end, through the central portion, to the distal end of the anchor and interstices within the frame along the axial length of the anchor;   a catheter configured to be inserted through the interior of the anchor, the catheter comprising one or more expandable members positioned on or proximate to a distal end of the catheter, wherein the one or more expandable members are sized to radially expand the proximal end of the anchor and the distal end of the anchor without expanding the central portion of the anchor;   wherein the interior of the anchor is configured to receive a rod for stabilizing the spine; and   wherein the anchor is configured such that when the distal end of the anchor is inserted into the interior of the second vertebrae and a volume of media is injected into the distal end of the anchor, the volume of media can flow through the interstices of the anchor outside the anchor and into the interior of the second vertebrae.   
     
     
         17 . The system of  claim 16 , wherein the expandable member is a balloon. 
     
     
         18 . The system of  claim 16 , wherein the catheter comprises a lumen configured for injecting the volume of media into the distal end of the anchor. 
     
     
         19 . The system of  claim 16 , wherein the central portion of the anchor is non-expandable or expandable to a maximal diameter less than the maximal diameter of the distal end of the anchor and less than a maximal diameter of the proximal end of the anchor. 
     
     
         20 . The system of  claim 16 , wherein the one or more expandable members comprises two expandable members. 
     
     
         21 . A method for stabilizing the spine, comprising:
 inserting an anchor into the interior of a first vertebral body, through an intervertebral disc, and into the interior of a second vertebral body adjacent the first vertebral body such that a distal end of the anchor is within the interior of the second vertebral body, a proximal end of the anchor is within the interior of the first vertebral body, and a central portion of the anchor spans the intervertebral disc, the anchor having a compressed configuration and an expanded configuration, wherein in the expanded configuration the proximal end and the distal end of the anchor have maximal expanded diameters at their widest portions of greater than the diameter of the central portion of the anchor, and wherein the distal end can be expanded without expanding the proximal end and the central portion and the proximal end can be expanded without expanding distal end and the central portion, the anchor being defined by an expandable frame forming an interior extending from the proximal end, through the central portion, to the distal end of the anchor and interstices within the frame along the axial length of the anchor;   inserting a catheter through the interior of the anchor, the catheter comprising one or more expandable members positioned on or proximate to a distal end of the catheter, wherein the one or more expandable members are sized to radially expand the proximal end of the anchor and the distal end of the anchor without expanding the central portion of the anchor;   expanding at least one of the one or more expandable members causing the distal end of the anchor to expand within the interior of the second vertebral body;   expanding at least one of the one or more expandable members the proximal end of the anchor to expand within the interior of the first vertebral body; and   flowing a volume of media into the distal end of the anchor within the interior of the second vertebral body, wherein the media flows through the interstices of the anchor outside the anchor and into the interior of the second vertebral body.