Instruments and methods for forming a cavity

Abstract

A cavity creating device having a cavity creating axis is introduced through a percutaneous access path into a cancellous bone volume, e.g., within a vertebral body. The cavity creating device is manipulated to form a cavity in the cancellous bone volume. The manipulation includes deflecting the cavity creating device along the cavity creating axis relative to the axis of the access path. A material, such as bone cement, can be conveyed into the cavity.

1 - 14 . (canceled) 
     
     
         15 . An instrument comprising:
 a catheter tube having a proximal end, a distal end, a first portion defining a first lumen, a second portion defining a second lumen, the first and second lumens being coaxial and having a circular cross-section; and   an expandable structure being disposed at the distal end of the catheter tube and having a proximal end, a distal end, and an outer surface and, the proximal end of the expandable structure is secured to the first portion and the distal end of the expandable structure is secured to the second portion, wherein the second portion extends through the first lumen of the catheter tube to the distal end of the expandable structure.   
     
     
         16 . An instrument as recited in  claim 15 , further comprising a stylet disposed with the second lumen. 
     
     
         17 . An instrument as recited in  claim 16 , wherein the stylet is removable from the second lumen. 
     
     
         18 . An instrument as recited in  claim 16 , wherein the stylet is slidably disposed within the second lumen. 
     
     
         19 . An instrument as recited in  claim 15 , wherein a space between the first and second lumens defines an unobstructed flow passage configured for delivery of a fill material into the expandable structure. 
     
     
         20 . An instrument as recited in  claim 15 , wherein no part of the catheter tube protrudes beyond the expandable structure when the expandable structure is in an expanded state. 
     
     
         21 . An instrument comprising:
 an outer catheter tube including a distal end and a first lumen having a substantially circular cross-sectional configuration;   an inner catheter tube extending within the outer catheter tube and including a distal end and a second lumen having a circular cross-sectional configuration, the first and second lumens being coaxial and the distal end of the inner catheter tube extending beyond the distal end of the outer catheter tube; and   an expandable structure communicating with the first lumen, the expandable structure having an outer surface, a proximal end secured to the first lumen, a distal end secured to a distal end of the second lumen wherein no portion of the outer catheter tube protrudes beyond the expandable structure such that the entire outer surface of the expandable structure is continuous.   
     
     
         22 . An instrument as recited in  claim 21 , wherein the expandable structure includes a proximal end and distal end and wherein the distal end of the expandable structure is attached to the distal end of the inner catheter tube. 
     
     
         23 . An instrument as recited in  claim 21 , further comprising a stylet disposed in the second lumen. 
     
     
         24 . An instrument as recited in  claim 23 , wherein the stylet includes a region with a preformed memory. 
     
     
         25 . An instrument as recited in  claim 23 , wherein the stylet includes a region having a bent configuration. 
     
     
         26 . An instrument as recited in  claim 23 , wherein the stylet includes a region having a bent configuration, the elongated member comprising a preformed memory such that the region returns to the bent configuration if straightened. 
     
     
         27 . An instrument as recited in  claim 21 , further comprising a guide sheath sized for through passage of the stylet and catheter tubes. 
     
     
         28 . An instrument as recited in  claim 21 , wherein the inner catheter tube is formed from a material more compliant than the material from which the outer catheter tube is formed. 
     
     
         29 . An instrument as recited in  claim 21 , wherein a space between the inner and outer catheter tubes defines an unobstructed flow passage configured for delivery of a fill material into the expandable structure. 
     
     
         30 . A method for creating a cavity in an interior body region of a patient, comprising:
 providing an instrument comprising:
 a catheter tube having a proximal end, a distal end, a first portion defining a first lumen, a second portion defining a second lumen, the first and second lumens being coaxial and having a circular cross-section, and 
 an expandable structure being disposed at the distal end of the catheter tube and having a proximal end, a distal end, and an outer surface and, the proximal end of the expandable structure is secured to the first portion, the distal end of the expandable structure is secured to the second portion and the second portion extends through the first lumen of the catheter tube to the distal end of the expandable structure; 
   positioning the expandable structure within the interior body region with the expandable structure in a collapsed configuration; and   moving the expandable structure from the collapsed configuration to an expanded configuration to create the cavity.   
     
     
         31 . A method as recited in  claim 30 , further comprising:
 positioning a guide wire in the interior body region; and   steering the instrument along the guide wire to a targeted region within the interior body region.   
     
     
         32 . A method as recited in  claim 30 , wherein moving the expandable structure from the collapsed configuration to the expanded configuration comprises delivering an inflation material through an unobstructed flow passage defined by a space between the first and second lumens and into an interior chamber of the expandable structure. 
     
     
         33 . A method as recited in  claim 30 , wherein the expandable structure has a first portion adjacent the proximal end of the expandable structure, a second portion adjacent the distal end of the expandable structure and a third portion between the first and second portions, the first and second portions each having a conical configuration and the third portion having a cylindrical configuration. 
     
     
         34 . A method as recited in  claim 30 , wherein no part of the catheter tube protrudes beyond the expandable structure when the expandable structure is in the expanded configuration.