This study will be conducted at 13 University Hospitals in France. The protocol has been approved by the institutional review board. After written informed consent, patients will be randomized, in the days after the fracture in 2 groups of 93 patients : 1) the control group (standard of care only: fixation by nail or external fixator and routine soft-tissue management) and 2) the study group (standard of care with percutaneous injection, one month after fracture, of autologous concentrated bone-marrow). Randomization will be stratified by severity of the open wound and by center. For the wound, strata A comprise Gustilo-Anderson types I, II and III-A and strata B, type III-B.