成纤维细胞在体外冲击波治疗骨不连愈合过程中的作用

The role of fibroblasts in bone healing with extracorporeal shock wave treatment

目的探讨成纤维细胞在体外冲击波治疗骨不连愈合过程中的作用。方法将30只日本大耳白兔制作骨不连模型(外固定支架固定),12周后经拍片证实共获得骨不连模型动物27只,随机分为治疗组(14只)和对照组(13只)。全麻下治疗组动物行体外冲击波治疗,在骨不连两断端相对应部位各冲击1000次,能量为0.54mJ/mm2,频率为60次/min,冲击波治疗一次完成。对照组仅行外固定支架固定。通过组织学及电镜观察冲击波治疗2周、6周骨不连断端成纤维细胞的成骨情况。结果体外冲击波造成骨不连断端的微骨折,启动骨不连的愈合状态;治疗组9例骨不连有8例愈合,对照组9例骨不连有3例愈合,经2检验,2值为5.84,P<0.05,差异有统计学意义。电镜下发现冲击波治疗2周后成纤维细胞与成骨细胞一样能够合成有周期性横纹的胶原纤维,冲击波治疗后6周形成骨陷窝,有明显的成骨作用。但在对照组却没有观察到明显的成骨作用。结论成纤维细胞在冲击波刺激下被激活,能够合成胶原纤维并形成骨陷窝,因此在骨不连愈合过程中起重要作用。

Objective To investigate the role of fibroblasts in nonunion fracture healing using extracorporeal shock wave（ESW） treatment. Methods Thirty healthy rabbits were selected to make the models of non-union fractures of the right tibias, which were then held apart by external fixation. 12 weeks after the operation, hypertrophic non-unions were confirmed in 27 of the rabbits by radiography. These 27 were divided randomly into a treatment group and a control group. The test animals were treated with ESW under general anaesthesia. The two ends of the nonunion fracture were shocked 1 000 times at 0.54 mJ/mm^2 and a frequency of 60 times/minute. The nonunions of the control group were treated with external fixations only. Histological examination and transmission electron microscopy（TEM） were conducted after 2 and 6 weeks. Standardized radiographs were taken after 12 weeks of the shock wave treatment. Results ESW induced microfractures, which initiated the healing process of the nonunionfractures. X-rays showed that 8 of the 9 fractures of the treatment group had healed after 12 weeks of EWS treatment, but only 3 of the 9 in the control group had healed. Statistical analysis showed that this difference was significant at the 5% level. After 2 weeks of ESW treatment, TEM showed many collagen fibers around the fibroblasts in the treatment group, with characteristic and periodic transverse lines. This indicated that the fibroblasts had been secreting collagen fibers as ostcoblasts. Six weeks later, osteoblasts and fibroblasts had formed bone lacunes, and they had become osteocytes. However osteogenetic activates were not found in the control group. Conclusions Fibroblasts are activated by ESW to better form bone tissue. This process plays an important role in rebuilding broken bones.