Revascularisation of fresh compared with demineralised bone grafts in rats

Revascularisation of bone grafts is influenced by both the anatomical origi n and the preimplantation processing of the graft. We investigated the reva scularisation by entrapment of Ce-141 (cerium) labelled microspheres in lar ge, fresh and demineralised syngeneic grafts of predominantly cancellous (i liac bone) or cortical (tibial diaphysis) bone three weeks after heterotopi c implantation in rats. The mean (SD) Ce-141 deposition index (counts per m inute (cpm) of mg recovered implant/cpm of mg host iliac bone) was higher i n fresh iliac bone grafts, 0.98 (0.46) compared to that of demineralised il iac bone, 0.32 (0.20), p < 0.001, and fresh tibial bone grafts, 0.51 (0.27) , p = 0.007. We found no significant difference in the mean Ce-141 depositi on index between fresh tibial bone grafts and demineralised tibial bone gra fts, 0.35 (0.42), p = 0.4, or between demineralised tibial grafts and demin eralised iliac bone grafts, p = 0.8. The results suggest that whereas fresh cancellous grafts are revascularised more completely than fresh cortical g rafts, there is no difference in the revascularisation of demineralised can cellous and cortical grafts. In addition, fresh cancellous bone is revascul arised more completely than demineralised cancellous bone, whereas there is no difference between fresh and demineralised cortical bone.