张力－应力下再生骨的超微结构研究

应用自制改良式Ｉｌｉｚａｒｏｖ外固定架对３０只山羊施行左胫骨骨干延长术。术后第７，１４，２１，２８，３５，４９和６３天分别各处死４只山羊。标本行光镜、电镜观察，发现张力－应力下骨延长骨发生符合膜内成骨，矿化沿定向胶原束逐渐形成板层骨，５～６周后成骨细胞出现，同时骨小梁直径增粗。愈合早期大多数成纤维细胞直接演变为骨细胞，在骨细胞的四周同时形成骨隐窝，使其发生可以不完全依赖于骨外膜及骨内膜的成骨细胞或骨生成细胞，能更早地在延长上、下端形成骨组织。说明成纤维细胞不仅产生胶原，而且在Ｉｌｉｚａｒｏｖ再生骨发生中起重要的作用。

Ultrastructural Investigation on the Regenerated Bone Under Tension-Stress Effect

A self-modified Ilizarov external fixator was applied for elongation of left tibia in 30 goats.Diaphyseal corticotomy and slow distraction were carried out by means of Ilizarov procedure.Each group of 4 goats was sacrificed on the 7th.14th,Z1st,28th,35th,49th and 63th postoperative days.Specimens were studied by light and electron microscopes.It was found that intramembranous ossification proceeded during the full course of distraction.Minerals depositting proceeded during the full course of distraction.Minerals depositting on the parallel collagen bundles formed lamellar bone.In the 5th to 6th week of distraction,osteoblasts appeared while the bony trabecula got thick.Most of fibroblasts transformed directly into osteocytes,surrounding which the lacuna occurred concomitantly in the early phase of ossification.This transformation makes distraction osteogenesis not entirely dependent on the osteogenic cells or osteoblasts of the endosteum and periosteum.In this way bone formation can take place earlier at the upper and lower edges of the gap.Consequently,fibroblasts do not only elaborate collagen fibrils,but also play an important role in Ilizarov distraction osteogenesis.