11th Yahya Cohen Memorial Lecture: An in vivo comparative study of the ability of derived mesenchymal stem cells in the treatment of partial growth arrest.

Few in vivo studies had previously been attempted in reaffirming the in vitro data in current literature. This study evaluated the ability of mesenchymal stem cells (MSCs) isolated from bone marrow, periosteum and fat to treat partial growth arrest in immature New Zealand white (NZW) rabbits. A physeal arrest model in an immature rabbit was created. The bony bridge was excised 3 weeks later, and MSCs from various sources were transferred into the physeal defect of different rabbits. Group I consisted of bone marrow-derived MSCs, Group II: periosteumderived MSCs, Group III: fat-derived MSCs. Contra-lateral tibiae, without undergoing operation, served as self-control. The animals were subsequently sacrificed, with radiological and histological analyses performed. All MSCs demonstrated chondrogenic and osteogenic differentiation potentials in vitro. In correction of varus angulation groups I and II exhibited superior results when compared to group III (P <0.05). The length discrepancies between operated and normal tibiae in groups I, II and III were significantly corrected when compared to the control group (P <0.01). In conclusion, bone marrow and periosteum derived stem cells provided better correction of physeal arrest in rabbits. The source of MSCs itself could influence the success in the treatment of growth arrest.