Study to Assess the Efficacy and Safety of Allogeneic Osteoblastic Cells (ALLOB®) Single Implantation in Tibial Fracture

Inclusion Criteria: 1. Men and women at least 18 years of age 2. Subject diagnosed with a fresh proximal, midshaft or distal tibial fracture with definitive reduction performed with nail(s) and wound closure within 1 week of fracture occurrence 3. Mechanism of injury at risk of DU/NU: fracture occurring because of a high energy impact 4. At increased risk of DU/NU defined by: * Severe open fracture (Gustilo-Anderson grade IIIa and IIIb) OR * Open (Gustilo-Anderson grade I-II) or closed (Tscherne grade II-III) fracture with at least one additional risk factor among smoking , comminuted fracture or cortical continuity (0-50%) 5. Ability to obtain a written, dated, and signed informed consent prior to any study related procedures and ability to understand and comply with study requirements Exclusion Criteria: 1. Definitive reduction at the fracture site under investigation performed with plate, screw or external fixator 2. Subjects who did not receive a standard antibiotic prophylaxis before definitive reduction at the fracture site under investigation 3. Intra-articular tibial pilon and/or plateau fracture at the site under investigation 4. Known osteomyelitis at the fracture site under investigation 5. Bone defect post-definitive reduction greater than 1cm at least on 2 cortices at the fracture site under investigation 6. Fracture requiring vascular surgery at the site under investigation 7. Pathological fractures as judged by the Investigator, such as tumor or metabolic bone disease 8. Bifocal or multifocal fracture at the site under investigation 9. Presence of fever (defined as body temperature ≥ 38°C) or other signs/symptoms suggestive of active infection before randomization 10. Severe brain trauma with a Glasgow Coma Scale (GCS) \[3 - 8\] or severe spinal cord injury with impossibility of weight-bearing 11. Current or history (within 5 years) of any neoplasia (except for basal cell carcinoma of the skin and for carcinoma in situ of the cervix that has been treated with no evidence of recurrence) 12. Known metabolic diseases potentially interfering with bone healing as judged by the Investigator, such as thyroid dysfunction, Paget disease or severe osteoporosis 13. Planned or history of solid organ transplantation or bone marrow transplantation 14. Known disease, including genetic disease, that may possibly need solid organ transplantation 15. Subject with renal impairment requiring dialysis or with clinically significant renal impairment defined as serum creatinine \>2.0 x ULN 16. Clinically significant hepatic function impairment defined as ALT/AST levels \> 3x ULN or total bilirubin levels \> 2 x ULN 17. Known hematologic disease as evidenced by hematocrit \< 25%, white blood cell \< 2,500/ul or platelet values \< 100,000/ul without another explanation 18. Subject with an history of long standing poorly controlled chronic hypertension or diabetes that could put him at risk of needing a kidney transplant later on according to the Investigator 19. History of hypersensitivity to human biological material including blood and blood derived products 20. Known allergy to DMSO, dextran, gentamicin and any other aminoglycosides 21. Participation in another interventional clinical study within 3 months prior to screening 22. Any chronic intake of medication within one month that might affect bone metabolism or the quality of bone formation such as but not limited to bisphosphonates, teriparatide, systemic steroids, anticoagulant therapies, methotrexate and other immunosuppressant drugs or related immunotherapy 23. Previous (within 10 years) treatment with bisphosphonates 24. Current treatment with bone morphogenic protein or any other osteo-biologic intervention at the site of the tibial fracture