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Objective To study the expression of basic fibroblast growth factor (bFGF) in ectopic osteogenesis of autogenetic minimal morselized bone so as to discuss the bone formation of minimal morselized bone. Methods All 48 rabbits were divided into two groups randomly. Then autogenetic minimal morselized bone and bulk bone were implanted into the muscle bag models of gluteus maximus muscle respectively. Samples were harvested on day 1,3,5,7,11,14,21 and 28 postoperatively and tested by the methods of histology, immunohistochemistry (IHC) and in situ hybridization (ISH). Results (1) The morselized bone grew faster than the bulk bone and was replaced by neonatal bone on the 28th day. In the group of bulk bone, the ability of osteogenesis was weaker dominated by bone absorption. (2) In the morselized bone group, the expression peaks of bFGF and bFGFmRNA appeared at day 5-7 postoperatively, mainly appeared in the mesenchymal cells, fibroblast, chondrocyte and osteoblast by the method of IHC and ISH. While in the group of bulk bone, the expressions of bFGF and bFGFmRNA were similar to those in the morselized bone group. The difference between the two groups was significant ( P
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Objective To study the efficacy of repairing bone defect with the composite of allogeneic morselized bone, bone morphogenetic protein(BMP)and collagen. Methods 1.5 cm long bone defect was created in each radius of 34 New Zealand rabbits. A composite of 200mg allogeneic minute morselized bone with 10 mg BMP and 0.2 ml collagen was placed into the bone defect of left radius in each rabbit (group A); the contralateral bone defect was filled with a composite of 200 mg allogeneic morselized bone and 0.2 ml collagen (group B). The bone mineral density(BMD)of the defects was evaluated at 8 and 12 weeks. The biomechanic tests were examined at 12 weeks. In group C, only 0.2 ml collagen was implanted as control. Results Radiological and histological examination revealed that the defects healed completely in both experimental groups, but there were more new bone formation, early bridging and rapid healing in group A compared with that of group B. The value of BMD in group A was higher than that in group B. The three-points bending test of group A showed that ultimate strength and bending stiffness were superior than that of group B, the anti- axial compressive stiffness as well; and the torsion rigidity and maximal torque of group A were also greater than that of group B. There were significantly statistic differences in all biomechanical tests between the two groups. Histological evaluations displayed that there were significant differences in matured level of new bone formation and remodeling process between two experimental groups. The new lamellar cortical bone formation was more matured, and the remodeling process was more perfect in group A comparing to that of group B, which might contribute to the better mechanical properties of group A. The defects did'nt achieve any osseous healing in control group. Conclusion The allogeneic morselized bone can be used effectively to repair segmental bone defects. The experiment suggests that the bone healing process can be promoted by the composite morselized bone graft with BMP and collagen.