Synergistic effect of hyperbaric oxygen therapy with parathyroid hormone [1-34] on calvarial bone graft in irradiated rat

Abstract

Purpose To determine the synergistic effect of parathyroid hormone [1-34] in combination with hyperbaric oxygen on bone graft in rat calvarial bone defect model under impaired osteogenic condition. Materials and Methods Twenty four rats were divided into 3 groups. Localized radiation with a single 12 Gy dose was administered to the calvarial. 4 weeks after radiation, calvarial circular defects were created in the parietal bones. All defects were filled with biphasic calcium phosphate. After grafting, parathyroid hormone was injected subcutaneously and hyperbaric oxygen therapy was administered. At 6 weeks after the bone graft, the rats were sacrificed and specimens were harvested. Results Histomorphometric evaluation showed the percent new bone area was higher in the PTH and PTH/HBO groups than in the Control group. Micro computed tomographic evaluation showed bone volume of new bone volume was higher PTH group than Control group. Bone surface in new bone volume was higher PTH/HBO group than Control group. In new bone volume, bone surface density was higher in the order of Control, PTH and PTH/HBO groups; all group was significant difference (P<0.017). Conclusions Within the limitations of this study, our data indicate that parathyroid hormone with hyperbaric oxygen may reverse the impairment of bone healing by irradiation.