Methods and devices that displace bone or other hard tissue to create a
cavity in the tissue. Where such methods and devices rely on a driving
mechanism for providing moving of the device to form a profile that
improves displacement of the tissue. These methods and devices also allow
for creating a path or cavity in bone for insertion of bone cement or
other filler to treat a fracture or other condition in the bone. The
features relating to the methods and devices described herein can be
applied in any region of bone or hard tissue where the tissue or bone is
displaced to define a bore or cavity instead of being extracted from the
body such as during a drilling or ablation procedure.