Heterotopic neo-osteogenesis from vascularized periosteum and bone grafts

Background: Periosteum is an osteogenic, flexible tissue. This study investigated the osteogenic potential of vascularized periosteal flaps in heterotopic conditions and compared it to the neo-osteogenesis from vascularized periosteal flaps combined with bone grafts with different properties. (autologous and xenograft). Methods: Vascularized periosteal flaps from the hindlimbs of 48 rabbits formed cylindrical pouches that were buried in muscles. The pouches were filled with autologous bone grafts (P/A group, n = 16), xenograft (P/X group, n = 16), or left empty (P/E group, n = 16). Specimens were harvested between 1 and 4 months and underwent radiographic, histologic, and histomorphometric evaluation. Results: The total surface area was larger in the groups combined with bone grafts. Osseous apposition did not differ significantly in the P/A and P/X groups (p > 0.05). The central cavity contained hematopoietic cells (P/A), xenograft (P/X), or was absent (P/E). Conclusion: Vascularized periosteal flaps presented strong osteogenic capacity in heterotopic conditions. Combination with bone grafts resulted in larger specimens. The quality of neo-osteogenesis was not influenced by the different properties of combined bone grafts.