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 withdefinitive reduction performed with nail(s) and wound closure within 1 week offracture occurrence
3. Mechanism of injury at risk of DU/NU: fracture occurring because of a high energyimpact
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) fracturewith at least one additional risk factor among smoking , comminuted fracture orcortical continuity (0-50%)

5. Ability to obtain a written, dated, and signed informed consent prior to any studyrelated 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 definitivereduction 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 thefracture 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 bonedisease
8. Bifocal or multifocal fracture at the site under investigation
9. Presence of fever (defined as body temperature ≥ 38°C) or other signs/symptomssuggestive of active infection before randomization
10. Severe brain trauma with a Glasgow Coma Scale (GCS) [3 - 8] or severe spinal cordinjury with impossibility of weight-bearing
11. Current or history (within 5 years) of any neoplasia (except for basal cell carcinomaof the skin and for carcinoma in situ of the cervix that has been treated with noevidence of recurrence)
12. Known metabolic diseases potentially interfering with bone healing as judged by theInvestigator, 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 organtransplantation
15. Subject with renal impairment requiring dialysis or with clinically significant renalimpairment defined as serum creatinine >2.0 x ULN
16. Clinically significant hepatic function impairment defined as ALT/AST levels > 3x ULNor 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 ordiabetes that could put him at risk of needing a kidney transplant later on accordingto the Investigator
19. History of hypersensitivity to human biological material including blood and bloodderived products
20. Known allergy to DMSO, dextran, gentamicin and any other aminoglycosides
21. Participation in another interventional clinical study within 3 months prior toscreening
22. Any chronic intake of medication within one month that might affect bone metabolism orthe quality of bone formation such as but not limited to bisphosphonates,teriparatide, systemic steroids, anticoagulant therapies, methotrexate and otherimmunosuppressant drugs or related immunotherapy
23. Previous (within 10 years) treatment with bisphosphonates
24. Current treatment with bone morphogenic protein or any other osteo-biologicintervention at the site of the tibial fracture