肥大型骨不连断端组织成骨潜能的实验研究

目的　观察肥大型骨不连断端及其周围区域组织的结构特点，评估其成骨潜能。 方法　收集2009年至2012年因肥大型骨不连在我院行手术治疗患者的骨不连断端标本共25例，通过光学显微镜及透射电镜观察不同区域的组织结构特点和微观特征。采用免疫组化检测BMP-2的表达，在高倍镜(400倍)下对阳性细胞进行观察并计数，并作统计分析。 结果　肥大型骨不连断端区域呈现出不同的组织类型，中心区主要是纤维化组织，其内可见大量的成纤维样细胞；边缘区可见大量的软骨细胞，可见少量的新生血管形成；骨痂区见有一定量的成骨细胞及丰富的新生血管。免疫组化染色显示肥大型骨不连断端中心区、周围区及骨痂区组织BMP-2的表达明显不同（P<0.05）。 结论　肥大型骨不连断端区域的组织及细胞类型呈现出不同的特点，BMP-2含量减少使得不同区域的成骨潜能不同。

Experimental study on bone formation potential of the intervening tissue at the hypertrophic nonunion site

Objective　To observe the structure of the intervening and surrounding tissue at the hypertrophic nonunion site, to assess the potential of bone formation.　Methods　Tissue from the nonunion site and its surroundings was extracted from 25 patients with hypertrophic nonunion. Tissue structure and microscopic characteristics of these regions were investigated by optical microscope, transmission electron microscopy. Expression of BMP-2 was detected by immunohistochemistry. The positive cells were observed, counted and analyzed statistically.　Results　The area of hypertrophic nonunion ends displayed different non-uniform histological features. The center area mainly displayed fibrotic tissue which contained a large number of fibroblast-like cells; the marginal area contained masses of chondrocytes without neovascularization; the scar area contained a certain amount of osteoblasts with rich neovascularization. The results of immunohistochemistry showed the expression of BMP-2 was more intense in the callus area than in the center area or in the marginal area(P<0.05).　Conclusion　Different area of hypertrophic nonunion ends displays different histological features and cytological characteristics. The decreasing of BMP-2 in the nonunion ends results in different potential of bone formation.