News of "fracture putty," an evolution in the use of scaffold material for bone regeneration: recent studies "show promise to significantly shorten the healing time and revolutionize the course of fracture treatment. ... Healing of critical-size defects is a major challenge to the orthopedic research community. Large-bone defects must be stabilized and necessitate technologies that induce rapid bone formation in order to replace the missing tissue and allow the individual to return to rapid function. To date, no single material can suffice. ... In our experiences with large animal models, following the guidelines established by our animal care and use committee, we have been successful in formulating a product that contains mesenchymal stem cells and allows them to survive in the environment of the fracture long enough to elicit the rapid formation of new bone. ... To start the bone regeneration process, the [researchers] used adult stem cells that produce a protein involved in bone healing and generation. They then incorporated them into a gel, combining the healing properties [into] 'fracture putty.' [The] team used a stabilizing device and inserted putty into fractures in rats. Video of the healed animals at two weeks shows the rats running around and standing on their hind legs with no evidence of injury. [The] researchers are testing the material in pigs and sheep, too. ... Our approach is biological with the putty. Other groups are looking at polymers and engineering approaches like implants and replacements which may eventually be combined with our approach. We are looking at other applications, too, using this gel, or putty, to improve spinal fusion outcomes."