同种异体骨移植后骨愈合的实验研究

目的：通过有关的动物实验来探讨有关异体骨移植骨愈合的规律，以达到加速异体骨移植骨愈合的目的。方法：24只新西兰大白兔为实验动物，随机分为实验组和对照组。实验组用梯度降温、深低温保存的股骨外侧髁植入，在接触的骨面置入骨形态发生蛋白(BMP)骨基质，以金属螺钉固定；对照组用取下的自体股骨外侧髁原位植入，用与实验组相同的内固定方法固定；术后4、8和12周行大体标本观察，并行苏木精-伊红(H-E)染色及BMP免疫组化染色，观察异体骨愈合的情况。结果：深低温保存的同种异体骨移植愈合与自体骨相似。BMP染色在新生骨及其周围类基质表达阳性。其愈合是从宿主骨向移植骨，从周围向中央，从哈佛管向其四周逐渐进行爬行替代的过程。结论：同种异体骨移植愈合过程主要通过骨传导实现成骨，骨诱导亦发挥积极作用。使用BMP、合适的内固定、大小适合的移植物，可以使异体骨愈合的过程与自体骨相似。

An experimental study to accelerate the healing of massive bone allografts

Objective:To investigate the mechanism and characteristics of massive bone allografts. Methods:Twenty-four New Zealand rabbits were randomly divided into experimental and control groups. In the experimental group, the bone defect was filled with a segment of osteoarticular allograft which was pretreated with gradient cooling and hypothermic freezer preservation, fixed with BMP and bolt needle. As for the control group, the osteoarticular autograft were inserted, and the bolt needle was applied, the follow-up times were four,eight, and twelve weeks. Bone repair progress were compared by gross specimen, hemaloxylin and eosin stain as well as immunohistochemical staining of BMP in the two groups at 4? 8? 12 weeks after transplantation. Results:The cryopreserved allograft was able to produce bone induction with BMP, suitable internal fixation, and proper size,the speed of the union is similar to that of autografts. New bone (osteoblasts and osteoid) was positive against BMP. The processes of the creep-substitution was from united end to the allogenic bone, from periphery to the center of the allografts and from Harversian canals to its periphery. Conclusion:The creep-substitution process depends on osteoconduction, but osteoinduction plays an important role in the healing of bone allografts. With BMP on the bone surface, suitable internal fixation and proper size of the allograft, the bone-healing processes of massive allografts is similar to that of the autografts.