股骨颈骨折愈合及股骨头活力的超微结构变化

目的：对股骨颈骨折的愈合过程及股骨头活力做超微结构研究。方法：２８只实验犬造成股骨颈骨折模型，加压螺丝钉固定组和对照组采用电镜和相关指标观察骨折愈合与股骨头的活力。结果：（１）股骨颈骨折愈合过程主要由骨髓的成骨作用完成；加压螺丝钉可缩小骨折间隙，有利于骨髓循环通过骨折端建立新的哈佛氏系统，加速网状骨向板层骨转化，缩短愈合时间。（２）内固定组和对照组在股骨头缺血４周均可见骨细胞变性，胞浆成份溶解空化；但６周后固定组开始有较多的血管向头内生长，成骨细胞大量增生，提示股骨头开始复活。而对照组骨细胞萎陷、坏死继续加重。结论：股骨颈骨折及时准确复位和良好的内固定，可加速骨折愈合和尽早使股骨头恢复活力。

Ultrastructural Feature of the Healing Process of the Femoral Neck Fracture and the Vitality of the Femoral Head

Aim: To investigate the ultrastructural feature of the healing process of the femoral neck fracture and the vitality of the femoral head. Methods: Twenty eight dogs with fracture of femoral neck were divided into two groups, the compressing screw fixing group and the control group. The ultrastructural features of the healing process and the vitality of the femoral head were observed under a transmission electron microscope and the functional indexes. Results: (1) The study suggested that the healing was chiefly due to the osteogenesis of the marrow, and that the fixation by the compressing screw could reduce the fracture gap and promote the circulation of the marrow which might be helpful to establish new Haversian system through the ruptured line to the impaired femoral head, and to accelerate the transformation of reticular bone to laminar bone, as a result, to shorten the healing time. (2) It was found that in both groups, there was osteocytic denaturation (such as dissolution and bubbling of the cytoplasm) around the fractured area 4 weeks post operation, but in fixing group, there were more capillaries from the neck to the head, and marked proliferation of osteogenic cells 6 weeks post operation, which implied that the femoral head began revival. Conclusion: The prompt and exact reduction and internal fixation can promote the healing process of the fracture of the femoral neck, and modify the vitality of the femoral head.