Systems and methods for treating bone using expandable bodies

Abstract

An expandable device is introduced into a cancellous bone volume of a vertebral body through a percutaneous access path. The expandable device carries a therapeutic substance. The expandable device is expanded while disposed within the cancellous bone volume to incorporate the therapeutic substance in the cancellous bone volume.

1 . A method comprising: 
 selecting a vertebral body for treatment, the vertebral body having a cortical wall enclosing a cancellous bone volume,    providing a therapeutic substance,    providing an expandable device including an expanded configuration and an unexpanded configuration,    placing the therapeutic substance on the expandable device,    introducing the expandable device into the vertebral body through a percutaneous access path while in the unexpanded condition,    expanding the expandable device while disposed within the cancellous bone volume from the unexpanded configuration toward the expanded configuration to incorporate the therapeutic substance in the cancellous bone volume.    
     
     
         2 . A method according to  claim 1   wherein expansion of the expandable device creates a cavity in the cancellous bone volume.    
     
     
         3 . A method according to  claim 2   further including placing a volume of filling material within the cavity.    
     
     
         4 . A method according to  claim 3   wherein the filling material hardens within the vertebral body.    
     
     
         5 . A method according to  claim 3   wherein the filling material comprises bone cement.    
     
     
         6 . A method according to  claim 1   further including controlling the expansion so that the expandable device expands more in an inferior-to-superior direction than in a lateral direction.    
     
     
         7 . A method according to  claim 6   wherein expansion is controlled by restraining expansion of the expandable device in the lateral direction.    
     
     
         8 . A method according to  claim 6   wherein expansion is restrained by providing restraints external to the expandable device.    
     
     
         9 . A method according to  claim 6   wherein expansion is restrained by providing restraints internal to the expandable device.    
     
     
         10 . A method according to  claim 6   wherein expansion is restrained by providing a wall on the expandable device that varies in wall thickness.    
     
     
         11 . A method according to  claim 1   wherein the expansion is capable of moving fractured cortical bone toward a desired anatomic position.    
     
     
         12 . A method according to  claim 1   wherein the expandable device expands by inflation.    
     
     
         13 . A method according to  claim 1   wherein the expandable device comprises a balloon.    
     
     
         14 . A method according to  claim 1   further including removing the expandable device from the vertebral body.    
     
     
         15 . A method according to  claim 1   wherein the therapeutic substance comprises an antibiotic, or a bone growth factor, or an osteoporosis drug.    
     
     
         16 . A system comprising 
 a therapeutic substance, and    an expandable device including an expanded configuration and an unexpanded configuration, the expandable device carrying the therapeutic substance, the expandable device being sized and configured for introduction into a vertebral body through a percutaneous access path while in the unexpanded condition, the vertebral body having a cortical wall enclosing a cancellous bone volume, the expandable device also being sized and configured for expansion while disposed within the cancellous bone volume from the unexpanded configuration toward the expanded configuration to incorporate the therapeutic substance in the cancellous bone volume.    
     
     
         17 . A system according to  claim 16   wherein expansion of the expandable device creates a cavity in the cancellous bone volume.    
     
     
         18 . A system according to  claim 16   further including a filling material and a tool for placing a volume of the filling material within the cavity.    
     
     
         19 . A system according to  claim 18   wherein the filling material hardens within the vertebral body.    
     
     
         20 . A system according to  claim 18   wherein the filling material comprises bone cement.    
     
     
         21 . A system according to  claim 16   wherein the expandable device is sized and configured, during expansion, to move fractured cortical bone toward a desired anatomic position.    
     
     
         22 . A system according to  claim 16   wherein the expandable device expands by inflation.    
     
     
         23 . A system according to  claim 16   wherein the expandable device comprises a balloon.    
     
     
         24 . A system according to  claim 16   wherein the therapeutic substance comprises an antibiotic, or a bone growth factor, or an osteoporosis drug.