RESUMO
PURPOSE: We observed new bone formation following the transplantation of allogenic periosteum-derived stem cells and different sizes of hydroxyapatite (HA) scaffold materials into rabbit long-bone defects. MATERIALS AND METHODS: Thirty-two white rabbits were grouped according to the material transplanted into their tibial bone defects: group 1 (microscale HA only); group 2 (nanoscale HA only); group 3 (microscale HA plus stem cells); and group 4 (nanoscale HA plus stem cells). Viscosity was controlled by the relative amounts of HA and agar. After surgery, radiologic, microscopic, and biochemical observations were performed weekly for 8 weeks. RESULTS: Nanoscale HA (groups 2 and 4) provided better bone formation than microscale HA (groups 1 and 3). The rabbits that had been transplanted with nanoscale HA plus stem cells (group 4) had more homogeneous bone formation during the natural repair process than the other groups. CONCLUSION: Further study is required using nanoscale HA plus organic substance and stem cells, which are more similar to human bone structure, for better bone formation.