Island Osteoperiosteal Flap Vitality when Isolated from Basal Bone by Silicone Interposition: An Experimental Study in Rabbit Tibia

Purpose: This study sought to confirm, through histologic evaluation, the vitality and viability of the island osteoperiosteal flap (i-flap) in a rabbit tibia model. Materials and Methods: In four rabbits, an osteotomy was performed on the tibial aspect of the right leg. A bone flap was raised, but the periosteal attachment was kept intact. The free-floating i-flap was separated from the rest of the bone by a silicone sheet. The rabbits were to be sacrificed after 1, 2, 4, and 8 weeks and histologic samples examined. Results: All surgeries were accomplished successfully; however, three animals showed fractured tibiae within a few days after surgery and were sacrificed immediately after the fractures were discovered. The fourth rabbit was sacrificed at 4 weeks. Histologic specimens showed vital new bone in the i-flap area and signs of remodeling in the transition zone and the original basal bone. Conclusion: The i-flap remained vital. This suggests potential for use in bone augmentation strategies, particularly for the alveolar split procedure. Keywords: alveolar split osteotomy, bone augmentation, island osteoperiosteal flap, rabbit model, tibia