Structures for creating cavities in interior body regions

Abstract

A shaft having an axis and a distal end portion is adapted to be deployed inside a vertebral body through a cannula. A filament is carried by the distal end portion. A surface on the filament is movable between a collapsed condition sized and configured to be deployed with the shaft through the cannula and an extended position that extends radially from the shaft. A mechanism is coupled to the filament to extend the filament in situ radially from the shaft into contact with cancellous bone within the vertebral body. The surface, when extended, defines a structure capable of forming a cavity wholly within the vertebral body in the cancellous bone.

1 . A system comprising 
 a cannula having an axis that establishes a percutaneous path leading into a vertebral body,    a shaft having an axis and a distal end portion adapted to be deployed inside the vertebral body through the cannula,    a filament carried by the distal end portion comprising a surface which is movable between a collapsed condition sized and configured to be deployed with the shaft through the cannula and an extended position that extends radially from the shaft, and    a mechanism coupled to the filament to extend the filament in situ radially from the shaft into contact with cancellous bone within the vertebral body, the surface, when extended, defining a structure capable of forming a cavity wholly within the vertebral body in the cancellous bone.    
     
     
         2 . A system according to  claim 1 , further including 
 a tool to convey a filling material into the cavity.    
     
     
         3 . A system according to  claim 1   wherein the surface carries at least one marker to aid visualizing the structure inside bone.    
     
     
         4 . A system according to  claim 1  wherein the structure, when extended, is deployed at an axis that transverses the axis of the shaft.  
     
     
         5 . A system according to  claim 1   wherein the shaft is flexible.