The present invention relates invention relates to devices and methods for the fixation and stabilization of orthopedic fractures and more specifically to stabilization of compression fractures of spinal vertebrae. The systems comprise cannulated orthopedic screws and mechanical expandable implants introducible through the lumen of such screws. In certain embodiments the cannulated implants are expandable within an intraosseous space to introduce scaffold-like structures such that subsequent introduction of a bone cement forms a composite in situ. The devices and methods are also particularly useful for stabilizing the orthopedic screws.