[New bone formation in an autologous spongy graft: an experimental morphological study].

Up to 5 days after an transplantation of autogenous cancellous bone in a defect of the ulna of dog which was stabilized by osteosynthesis no remarkable osteoblastic cell activity can be made out by light microscopy using the semithin sectioning technique. On the other hand, there is an obvious increase of osteogenic cells which normally only occur in small numbers in adult dog's cancellous bone of the iliac crest. Only after 7 days, numerous typical osteoblasts can be detected in association with transplanted cancellous chips, osteoblasts which seem to originate from the osteogenic cells by mitotic divisions. One week after the test's commencement, an extensive revascularisation of the transplant can be noticed as well. The osteoblastic cell activity and the forming of new bone are obviously dependent on a sufficient vascular supply in autogenous cancellous graft. The high osteogenic power of an autogenous cancellous graft is based on the ability of survival of the osteogenic cells, which proliferate and differentiate into osteoblasts in the course of one week, wherever its are close enough to functioning capillaries.