同种异体皮质骨和松质骨愈合的组织学研究

目的探讨同种异体皮质骨和松质骨愈合方式的差异。方法兔左侧尺骨中段植人冻干异体骨，分为皮质骨组和松质骨组，均为32只。术后2、4、8、16周分批处死，取材进行Ⅰ型胶原基因的原位杂交研究，以及皮质骨孔隙率和松质骨平均小梁宽度的组织学定量分析。结果异体皮质骨内先出现大量的骨吸收陷窝，然后在陷窝内出现表达1型胶原mRNA的成骨细胞；其孔隙率先增大，然后缓慢减小。异体松质骨内早期就有大量表达五型胶原mRNA的成骨细胞沉积在原有骨小梁表面，附近同时有破骨细胞的活动；其平均小梁宽度持续上升。结论同种异体皮质骨的愈合是在吸收的基础上成骨，而同种异体松质骨内则可以直接成骨。

A Comparative Study on the incorporation of Conical Allograft with That of Cancellous Allograft

Objective To explore the difference of incorporation pattern of conical allograft and cancellous allograft. Methods Freeze - dried allograft were transplanted to left side of the midshaft diaphyseal ulnar respectively in each group of 32 rabbits. Animals were killed in batch at two. four. eight and sixteen weeks after transplantation and specimens were taken for in situ hybridization of the type I collagen gene and the histomorphometric analysis of porosity of conical bone and mean widths of trabeculae. Results Many bone resorptive cavities occured early in the conical allograft followed by the appearance of osteoblast expressing type I mRNA. The bone porosity increased gradually and then decreased slowly. A lot of osteoblast expressing type I mRNA deposited on the surface of old trabeculae at the early stage and osteoclasts could be observed nearly simultaneously. The mean widths of trabeculae increased constantly. Conclusion The osteogenesis of conical allograft is based on the osteoclastic resorption while new bone could be formed directly in cancellous allograft.