[Experimental study of repairing segmental bone defect with reconstituted freeze-dried bone allograft].

OBJECTIVE: To study the effect of basic fibroblast growth factor (bFGF) and hyaluronic acid gel (HAG) combined with freeze-dried bone allograft in repairing segmental bone defect and to explore their mechanism. METHODS: The 15 mm segmental bone/periosteum defects were created on bilateral radius in 50 New Zealand rabbits and were treated with four different kinds of implants on 25 radius respectively (group A: bFGF and HAG combined with freeze-dried bone; group B: bFGF combined with freeze-dried bone; group C: HAG combined with freeze-dried bone; group D: simple freeze-dried bone as a control). The repair of defect was observed radiologically and histologically and were analyzed by radionuclide bone imaging and measurement of calcium contents at different periods. RESULTS: The new bone formation, bone metabolic activity and calcium contents of defects were higher in group A than in group B (P < 0.05), and were higher in group B than in groups C and D (P < 0.05). There were no significant difference between groups C and D. The bone defects healed in the 8th week in group A, in the 10th week in group B, but did not healed in the 10th week in groups C and D. CONCLUSION: As an osteogenetic factor, bFGF promotes the new bone formation; as a slow-release carrier, HAG enhances the effectiveness of bFGF. The combination of bFGF, HAG and freeze-dried bone allograft can repair the segmental bone defect more effectively.

[Experimental study on stimulation of guided bone regeneration by autogenous bone marrow].

OBJECTIVE: To study the effect of autogenous bone marrow on guided bone regeneration (GBR), and evaluate the repairing ability of GBR in bone defect with autogenous bone marrow. METHODS: Ten mm segmental defects were produced in both radii of 18 rabbits. The defect was bridged with a silicon tube. Autogenous bone marrow was injected into the tube on the experimental group at 0, 2, 4 weeks after operation, and peripheral blood into the control group at the same time. The X-ray, gross, histological and biochemical examinations were observed in various times. RESULTS: The new bone formation of experimental group was prior to that of control group; calcium and alkaline phosphatase of experimental group were higher than those of control group. The experimental group had all been healed at the tenth week, but no one healed in control group. CONCLUSION: It can be conclude that autogenous bone marrow can stimulate bone formation and facilitate GBR in bone defect.