Spine distraction implant and method

Abstract

A spine distraction implant alleviates pain associated with spinal stenosis and facet arthropathy by expanding the volume in the spine canal and/or neural foramen. The implant provides a spinal extension stop while allowing freedom of spinal flexion.

1 . A method, comprising:
 accessing a space between adjacent spinous processes of a spinal column from a first side of a first spinous process and from a first side of a second spinous process that is adjacent the first spinous process;   positioning at least a portion of an implant within the space between the first spinous process and the second spinous process, the implant further having a first arm, a second arm and a flexible tether, the portion of the implant being disposed between the first arm and the second arm of the implant; and   disposing the flexible tether about a first spinous process.   
     
     
         2 . The method of  claim 1 , wherein:
 the first arm is adjacent the first side of at least a first spinous process from the adjacent spinous processes or a second spinous process; and   the second arm is adjacent a second side opposite the first side of at least the first spinous process or the second spinous process.   
     
     
         3 . The method of  claim 1 , wherein:
 the portion of the implant has a longitudinal axis;   at least one of the first arm and the second arm has a dimension along an axis normal to the longitudinal axis greater than a dimension of the portion of the implant along the axis normal to the longitudinal axis.   
     
     
         4 . The method of  claim 1 , wherein the implant has a first opening, the flexible tether is coupled to a first end portion of the implant, the method further comprising:
 positioning the flexible tether through the first opening.   
     
     
         5 . The method of  claim 1 , wherein the flexible tether is a first flexible tether, the implant further has a second flexible tether, the method further comprising:
 disposing the second flexible tether about the second spinous process.   
     
     
         6 . The method of  claim 1 , wherein the flexible tether is a first flexible tether, the implant further has a second flexible tether, the implant has a first opening and a second opening, the first flexible tether is coupled to a first end portion of the implant, the second flexible tether is coupled to the second end portion of the spacer, the method further comprising:
 positioning the first flexible tether through the first opening;   disposing the second flexible tether about the second spinous process; and   positioning the second flexible tether through the second opening.   
     
     
         7 . The method of  claim 1 , wherein the flexible tether is a first flexible tether, the implant further has a second flexible tether, the first flexible tether has a first end and a second end, the first end of the first flexible tether being coupled to the implant, the second end of the first flexible tether is positioned with respect to the first opening such that a length of the first flexible tether between its first end and the first opening is substantially fixed, the method further comprising:
 disposing the second flexible tether about the second spinous process, the second flexible tether has a first end and a second end, the first end of the second flexible tether being coupled to the implant, the second end of the second flexible tether is positioned with respect to the second opening such that a length of the second flexible tether between its first end and the second opening is substantially fixed.   
     
     
         8 . The method of  claim 1 , wherein the flexible tether is a first flexible tether, the implant further has a second flexible tether, the first flexible tether has a first end and a second end, the first end of the first flexible tether being coupled to the implant, the second end of the first flexible tether is positioned with respect to the first opening such that a length of the first flexible tether between its first end and the first opening is substantially fixed, the method further comprising:
 disposing the second flexible tether about the second spinous process, the second flexible tether has a first end and a second end, the first end of the second flexible tether being coupled to the implant, the second end of the second flexible tether is positioned with respect to the second opening such that a length of the second flexible tether between its first end and the second opening is substantially fixed,   the length of the first flexible tether and the length of the second flexible tether each is substantially fixed such that the first spinous process and the second spinous process have a range of motion relative to each other.   
     
     
         9 . The method of  claim 1 , wherein the flexible tether is a first flexible tether, the implant further has a second flexible tether, the first flexible tether has a first end and a second end, the first end of the first flexible tether being coupled to the implant, the second end of the first flexible tether is positioned with respect to the first opening such that a length of the first flexible tether between its first end and the first opening is substantially fixed, the method further comprising:
 disposing the second flexible tether about the second spinous process, the second flexible tether has a first end and a second end, the first end of the second flexible tether being coupled to the implant, the second end of the second flexible tether is positioned with respect to the second opening such that a length of the second flexible tether between its first end and the second opening is substantially fixed,   the length of the first flexible tether and the length of the second flexible tether each is substantially fixed such that the first flexible tether and the second flexible tether collectively do not inhibit forward bending and collectively allow spinal column flexion with respect to the first spinous process and the second spinous process.   
     
     
         10 . A method, comprising:
 accessing a space between adjacent spinous processes of a spinal column from a first side of the adjacent spinous processes, the adjacent spinous processes including a first spinous process and a second spinous process;   positioning a portion of an implant within the space between the adjacent spinous processes such that a first arm of the implant is adjacent the first side of at least the first spinous process or the second spinous process and such that a second arm of the implant is adjacent a second side opposite the first side of at least the first spinous process or the second spinous process, the implant further having a flexible tether; and   disposing the flexible tether about the first spinous process.   
     
     
         11 . The method of  claim 10 , wherein the portion of the implant includes a central portion of the implant disposed between the first arm and the second arm. 
     
     
         12 . The method of  claim 10 , wherein:
 the portion of the implant includes a central portion of the implant disposed between the first arm and the second arm,   the central portion of the implant has a longitudinal axis,   at least one of the first arm and the second arm has a dimension along an axis normal to the longitudinal axis greater than a dimension of the central portion along the axis normal to the longitudinal axis.   
     
     
         13 . The method of  claim 10 , wherein the implant has an end portion and an opening, the flexible tether having a first end and a second end, the first end of the flexible tether being connected to the end portion, the method further comprising:
 positioning the second end of the tether through the opening of the implant while the flexible tether is disposed about the first spinous process.   
     
     
         14 . The method of  claim 10 , wherein the implant has an end portion and an opening, the flexible tether having a first end and a second end, the first end of the flexible tether being connected to the end portion, the method further comprising:
 tying off the second end of the flexible tether with respect to the opening such that a length of the flexible tether between its first end and the opening is substantially fixed.   
     
     
         15 . The method of  claim 10 , wherein:
 the implant has an end portion and an opening, the flexible tether having a first end and a second end, the first end of the flexible tether being connected to the end portion,   the second end of the flexible tether is positioned such that the flexible tether does not inhibit forward bending and allows spinal column flexion with respect to the first spinous process and the second spinous process.   
     
     
         16 . The method of  claim 10 , further comprising:
 guiding motion of the first spinous process and the second spinous process relative to each other such that the implant limits extension and allows flexion.   
     
     
         17 . A method, comprising:
 forming an incision between adjacent spinous processes from a first side of adjacent spinous processes;   guiding a first arm and a central portion of an implant between the adjacent spinous processes through the incision; and   positioning the implant such that a second arm of the implant is adjacent the first side of at least the first spinous process or the second spinous process and such that the first arm is adjacent a second side opposite the first side of at least the first spinous process or the second spinous process.   
     
     
         18 . The method of  claim 17 , wherein:
 the central portion of the implant has a longitudinal axis,   at least one of the first arm and the second arm has a dimension along an axis normal to the longitudinal axis greater than a dimension of the central portion along the axis normal to the longitudinal axis.   
     
     
         19 . The method of  claim 17 , wherein the implant has a first flexible tether and a second flexible tether, the method further comprising:
 disposing the first flexible tether about the first spinous process; and   disposing the second flexible tether about the second spinous process.   
     
     
         20 . The method of  claim 17 , wherein the implant has a first flexible tether and a second flexible tether, the method further comprising:
 disposing the first flexible tether about the first spinous process;   tying off an end of the first flexible tether to the implant such that the length of the first flexible tether is substantially fixed during a range of motion of the first spinous process and the second spinous relative to each other;   disposing the second flexible tether about the second spinous process; and   tying off an end of the second flexible tether to the implant such that the length of the second flexible tether is substantially fixed during the range of motion of the first spinous process and the second spinous relative to each other.   
     
     
         21 . The method of  claim 17 , wherein the implant has an end portion and a tether, the end portion of the implant having a first side and a second side opposite the first side, the tether having a first end portion and a second end portion, the first end portion of the tether being connected to the first side of the end portion of the implant; and
 tying off the second end portion of the tether at the second side of the end portion of the implant such that the tether is disposed about the first spinous process.   
     
     
         22 . The method of  claim 17 , wherein the implant has a tether, the implant has an opening associated with the second side of the end portion of the spacer, the method further comprising:
 positioning, before the tying, the second end of the tether through the opening of the implant, a length of the tether between its first end portion and the opening being substantially fixed.   
     
     
         23 . The method of  claim 17 , further comprising:
 guiding motion of the first spinous process and the second spinous process relative to each other such that the implant limits extension and allows flexion.