Vertebral body bone marrow aspirate (V-BMA), easily accessible simultaneously with the preparation of the site for pedicle screw insertion during spinal procedures, is becoming an increasingly used cell therapy approach in spinal surgery. However, the main drawbacks for V-BMA use are the lack of a standardized procedure and of a structural texture with the possibility of diffusion away from the implant site. the aim of this study was to evaluate, characterize and compare the biological characteristics of MScs from clotted V-BMA and MScs from whole and concentrate V-BMAs. MScs from clotted V-BMA showed the highest cell viability and growth factors expression (tGf-β, VeGf-A, FGF2), the greatest colony forming unit (CFU) potency, cellular homogeneity, ability to differentiate towards the osteogenic (COL1AI, TNFRSF11B, BGLAP) and chondrogenic phenotype (SOX9) and the lowest ability to differentiate toward the adipogenic lineage (ADIPOQ) in comparison to all the other culture conditions. Additionally, results revealed that MSCs, differently isolated, expressed different level of HOX and TALE signatures and that PBX1 and MEIS3 were down-regulated in MSCs from clotted V-BMA in comparison to concentrated one. The study demonstrated for the first time that the cellular source inside the clotted V-BMA showed the best biological properties, representing an alternative and advanced cell therapy approach for patients undergoing spinal surgery. Bone marrow aspiration is an easy, safe and inexpensive method that makes possible a direct transplantation of mesenchymal stem cells (MSCs), endothelial progenitor cells, hematopoietic stem cells, other progenitor cells, growth factors, e.g. bone morphogenetic proteins (BMPs), platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and several interleukins, into the defect site 1-3. Despite only a very small percentage (0.01-0.001%) of MSCs is found among the totality of mononuclear cells in bone marrow aspirate (BMA), the attendance of non-adherent osteogenic cells and the potential collaboration among BMA cell types in tissue repair suggest that the use of whole BMA, instead of expanded, concentrated and purified MSCs, is preferable for bone cell therapy 4. Recently the use of iliac crest BMA is becoming increasingly trendy also in spinal surgery in order to overcome the problems linked to the harvest and use of iliac crest autograft and/or local autograft (spinous processes, laminae) 5,6. However, several issues of the process need specific attention in order to optimize the efficacy and reduce potential side effects 7. In addition, although bone marrow is commonly aspirated by the iliac crest, during spinal surgery its harvest leads to an increase in operative and rehabilitation time and to further morbidity in the donor site 8. These complications are particularly critical in adolescent idiopathic scoliosis patients who have no pain before surgery and in osteoporotic patients that have a greatest risk of bleeding comp...