Osteogenic capacity of vascularised periosteum: an experimental study on mandibular irradiated bone in rabbits.

Background: Free flaps are presently the best way to treat advanced mandibular ostonecrosis. Nevertheless, the functional and morphological results can be improved. To avoid a mandibular resection, a free periosteal flap was envisioned. In a preliminary study, the authors opted for a pedicled periosteal flap and evaluated the effect of the latter on regeneration of a rabbit irradiated mandibular bone.

Methods: Two bone fragments were taken from the basilar part of the mandible of 15 rabbits through skin incision. Those fragments were then exposed to a 30-Gy irradiation. One bone fragment was implanted in a pedicled periosteal flap elevated from the medial aspect of the femur while the other was subcutaneously fixed as a control. We retrieved the fragments at day 10, 20, 30 and 90 to make a histological analysis without prior decalcification using histomorphometry technique.

Results: In the periosted fragments, an increased osteoblastic and osteoclastic activity as well as neovascularisation evoked intense remodelling. In the subcutaneous fragments, bone resorption was much more important than osteogenesis and vessels were absent.

Conclusion: We have concluded than periosteum, which has already been proven to be efficient in normal bone regeneration, can be just as such efficient in irradiated bone regeneration.