Method and apparatus for spinal stabilization

Abstract

A method and apparatus of limiting at least one degree of movement between a superior vertebrae and an inferior vertebrae of a patient includes advancing a distal end of a stabilization device into a pedicle of the inferior vertebrae. A proximal portion of the stabilization device is positioned such that the proximal portion limits at least one degree of movement between a superior vertebrae and an inferior vertebrae by contacting a surface of the superior vertebrae.

1 - 20 . (canceled) 
     
     
         21 . A spinal stabilization device, comprising:
 an elongate body, having a proximal end and a distal end;   a distal anchor on the distal end of the elongate body;   a proximal anchor moveably carried by the elongate body, wherein the proximal anchor is configured to rotate with respect to the elongate body,   wherein the proximal anchor and the elongated body include complementary retention structures which allow distal movement of the proximal anchor but resist proximal movement of the proximal anchor.   
     
     
         22 . The spinal stabilization device of  claim 21 , wherein the proximal anchor comprises a truncated sphere. 
     
     
         23 . The spinal stabilization device of  claim 21 , wherein the complementary retention structures comprise a series of annular ridges or grooves. 
     
     
         24 . The spinal stabilization device of  claim 21 , wherein the distal anchor comprises threads. 
     
     
         25 . The spinal stabilization device of  claim 21 , wherein as the proximal anchor rotates, the axial position of the proximal anchor with respect to the elongate body remains fixed. 
     
     
         26 . The spinal stabilization device of  claim 21 , wherein the tendency of the elongate body to rotate is reduced. 
     
     
         27 . The spinal stabilization device of  claim 21 , wherein the proximal anchor comprises an annular recess configured to rotate about a structure within the annular recess. 
     
     
         28 . A spinal stabilization device, comprising:
 an elongate body, having a proximal end and a distal end;   a distal anchor on the distal end of the elongate body;   a proximal anchor moveably carried by the elongate body,   an anti-rotational feature configured to prevent or limit rotation of the proximal anchor with respect to the elongate body,   wherein the proximal anchor and the elongated body include complementary retention structures which allow distal movement of the proximal anchor but resist proximal movement of the proximal anchor.   
     
     
         29 . The spinal stabilization device of  claim 28 , wherein the proximal anchor comprises a truncated sphere. 
     
     
         30 . The spinal stabilization device of  claim 28 , wherein the complementary retention structures comprise a series of annular ridges or grooves. 
     
     
         31 . The spinal stabilization device of  claim 28 , wherein the distal anchor comprises threads. 
     
     
         32 . The spinal stabilization device of  claim 28 , wherein the anti-rotational feature comprises a key. 
     
     
         33 . The spinal stabilization device of  claim 28 , wherein the anti-rotational feature comprises a spline, groove, or flat side. 
     
     
         34 . A spinal stabilization device, comprising:
 an elongate body, having a proximal end and a distal end;   a distal anchor on the distal end of the elongate body;   a proximal anchor moveably carried by the elongate body, wherein the proximal anchor comprises a truncated sphere,   wherein the proximal anchor and the elongated body include complementary retention structures which allow distal movement of the proximal anchor but resist proximal movement of the proximal anchor.   
     
     
         35 . The spinal stabilization device of  claim 34 , wherein the proximal anchor is configured to rotate with respect to the elongate body. 
     
     
         36 . The spinal stabilization device of  claim 35 , wherein as the proximal anchor rotates, the axial position of the proximal anchor with respect to the elongate body remains fixed. 
     
     
         37 . The spinal stabilization device of  claim 34 , further comprising an anti-rotational feature configured to prevent or limit rotation of the proximal anchor with respect to the elongate body. 
     
     
         38 . The spinal stabilization device of  claim 37 , wherein the anti-rotational feature comprises a key, a spline, groove, or flat side. 
     
     
         39 . The spinal stabilization device of  claim 34 , wherein the complementary retention structures comprise a series of annular ridges or grooves. 
     
     
         40 . The spinal stabilization device of  claim 34 , wherein the distal anchor comprises threads.