STEM CELLS FOR FRACTURE HEALING
Nonunion occurs when a fracture has failed to heal in the expected time. Because the expected time is hard to define and arbitrary, it is better defined as when further progress in bone healing will not occur without intervention (Bolhofner, 2010). Nonunion of fracture may be caused by uncontrolled movement of the fracture site or by acellular environment. Bone marrow aspirate from the illiac crest has been applied to nonunion sites with limited morbidity (Gomez-Barrena et al., 2011)