a vertebral body is selected for treatment . the vertebral body has a cortical wall enclosing a cancellous bone volume . the vertebral body has at least one cortical plate that is depressed due to fracture . at least one maximum dimension for the cancellous bone volume is ascertained . an expandable device is provided having an expanded configuration and an unexpanded configuration . the expandable device has a predefined dimension when substantially expanded that is less than the maximum dimension . the expandable device is introduced into the vertebral body through a percutaneous access path while in the unexpanded condition . the expandable device is expanded while disposed within the cancellous bone volume from the unexpanded configuration toward the expanded configuration to create a cavity that occupies less than the cancellous bone volume .