[Experimental study of repairing skull defect with autogenous cranial bone dust]

To build animal model of skull defect for the basic research of skull defects reconstruction with autogenous cranial bone dust and its relevance to the clinical application.

Three full-thickness parietal skull defects (A, B and C) were created in 30 New Zealand white rabbits. The size of all the defects was 1 cm in diameter. The defect A was left untreated as control. Defects B and C were reconstructed with autogenous cranial bone dust. Two pieces of pyroxylin membrane were placed on the top and bottom of the defect B. every 10 rabbits were killed for analysis at 4, 8, 12 weeks after operation.

Defect A was largely repaired with connective tissue. Defect B was repaired rapidly with newly formed cancellous bone in the early period, but the following process of the growth, remodeling and maturing of the newly-formed cancellous bone was slowly. The bone ingrowth in defect C was more mature, but could not repair the defect completely, especially in the central zone. The grafted bone dust was absorbed gradually. Active angiogenesis could be observed in the newly formed bone. For the same defect, new bone had a greater amount of calcium at 12 weeks than at 4 and 8 weeks after operation (P < 0.05). And the calcium content of new bone was higher in defect C than in defect B at 8, 12 weeks after operation (P < 0.05).

The osteogenesis and angiogenesis are closely related to the time and location. The pyroxylin membrane can significantly promote the formation of cancellous bone in defect with autogenous bone dust graft during the early period.