For the study group, the injection is scheduled at 1 month ± 5 days after the fracture. The techniques have been described by Hernigou (J Bone Joint Surg Am, 2006; 88(sup 1 part 2): 322-327). There are 3 steps: marrow aspiration (300 - 500 g) from iliac crest under general anesthesia, centrifugation in cell therapy unit to obtain a concentrated buffy coat of about 50 ml containing progenitor cells and other mononuclear cells, percutaneous injection in the fracture site of 20-30 ml of the buffy coat under fluoroscopy control.