Objective: To study the effect of combined use of autologous micro-morselized bone with bone morphogenetic protein(BMP) and type I collagen graft on the treatment of segmental bone defects.
Methods: The bulk bone of rabbit iliac crest was ground into micro-morselized bone, which was combined with BMP and type I collagen. The model of 1.5 cm bone defect was established in the middle shaft of the radius. Fifty-six rabbits were assigned to four repairing methods: autologous micro-morselized bone graft with BMP and type I collagen, autologous micro-morselized bone graft with type I collagen, autologous micro-morselized bone graft alone, and control group. The defect-repairing capability of each group was assessed by radiographic, histological, bone densitometry and biomechanical studies.
Results: X-ray manifested that at the end of 8 weeks after operation, the bone defect treated with autologous micro-morselized bone graft with BMP and type I collagen was repaired completely, and at the end of 12 weeks after operation the bone defect treated with autologous micro-morselized bone and type I collagen was cured completely, but the bone defect treated with autologous micro-morselized alone was completely repaired. No healing was found in the control group. In the bone densitometry detection, the material with BMP exhibited the strongest defect-repairing capability in terms of amount increased and quality of the new bone at the end of 8 weeks and 12 weeks. The group with BMP has the best mechanical strength of all groups at the end of 12 weeks.
Conclusion: Autologous micro-morselized bone graft with BMP/type I collagen and autologous micro-morselized bone graft with type I collagen prove to be effective in repairing segmental bone defects. The autologous micro-morselized bone combined BMP and type I collagen is an excellent bone repairing material considering the satisfactory osteogenesis, osteo-conduction, and osteo-induction seen in this method.