Early injection of autologous bone marrow concentrates decreases infection risk and improves healing of acute severe open tibial fractures.

Introduction: Open fractures are at risk of nonunion; surgeons are reluctant to propose early standard bone grafting after open fractures, preferring to wait in order to adequately assess the facture status of infection. Bone marrow contains mesenchymal stem cells (MSCs) and granulocyte and macrophage precursors identified in vitro as colony forming units-granulocyte macrophage (CFU-GM), both of which have a prophylactic action against infection. We therefore tested the hypothesis that early injection of bone marrow concentrate would be useful in these fractures.

Methods: We evaluated a series of 231 patients who had received early percutaneous implantation of bone marrow concentrate (BMC) to treat open fractures (with gap less than 10 mm) that were Gustilo-Anderson Type II or III. The results were compared with those of 67 control (no early graft) patients and with those of 76 patients treated with an early, standard of care, iliac bone graft. All patients were treated with external fixation and were considered to have an aseptic fracture at the time of early grafting, but the actual status of infection was re-assessed at the time of grafting by histology and/or analysis of the aspirate. The bone marrow graft contained after concentration 49,758 ± 21,642 CFU-GM-derived colonies/cc and 9400 ± 1435 MSCs/cc which represents an important increase compared to the level of CFU-GM cells and MSCs present in a standard auto-graft. Healing was evaluated at 9 months.

Results: The rate of unsuspected infections was higher than 15% in the 3 groups. Bone union and removal of external fixation was achieved at 9 months by 50.7% of patients in the Control Group, by 86.8% of patients in the group with a standard bone graft, and by 87.4% of patients in the bone marrow group. A 90% risk reduction (p = 0.005) in the need for an invasive standard bone graft to treat a nonunion and in the risk of infection was observed when bone marrow was proposed as early injection to the treatment of type II or type-III tibial fractures.

Conclusion: Bone marrow concentrate for early grafting in open fractures with limited gap was efficient for healing while decreasing infection.