海水浸泡开放性骨折伤愈合过程中组织病理学和血管内皮细胞生长因子(VEGF)表达

目的通过观察普通开放骨折、海水浸泡开放骨折愈合过程的组织学变化和骨痂中血管内皮细胞生长因子(VEGF)的表达,了解海水浸泡开放性骨折愈合过程VEGF的作用与机制。方法新西兰大白兔59只,随机分为普通开放骨折组(对照组)24只和海水浸泡开放骨折组(实验组)35只。造成桡骨横行1.5mm缺损完全开放骨折,普通开放骨折伤组旷置3h,海水浸泡开放骨折伤组海水浸泡伤口3h,之后依次缝合伤口。于第1、3、7、14、21、28、45天处死动物。观察海水浸泡开放骨折伤在骨折愈合中不同时间的病理过程。采用RT-PCR方法检测普通开放骨折、海水浸泡开放骨折不同阶段骨痂中的VEGF的表达及变化。结果海水浸泡开放骨折伤骨痂形成延迟,骨折后第28天,对照组断端间骨痂为骨性骨痂者8例,为软骨者4例,实验组断端间骨痂为骨性骨痂者6例,为软骨者14例。海水浸泡骨折伤愈合过程中新生骨痂的VEGF表达在骨折后逐渐升高,术后14d达到高峰,之后逐渐下降,但在28d时仍保持较高水平,与一般开放骨折愈合过程的VEGF表达无显著差异(P>0.05)。结论海水浸泡使骨折骨痂形成不良率增高,骨折愈合过程有延迟倾向;但骨折愈合过程中VEGF表达无明显变化。

Histopathology and expression of VEGF in callus during the healing process of open fracture under seawater immersion

Objective To observe the histopathology and the expression of VEGF in callus during healing process of open fracture under seawater immersion. Methods 59 New Zealand rabbits were randomized into 2 groups. The mode of transverse open fracture of the radius was made for all the animals. The wounded limbs of the 24 rabbits in the control group were exposed in the air for 3 hours, while those of the other 35 rabbits in the experimental group were immersed under seawater for 3 hours. Finally, debridement was conducted and the wounds were treated in both groups. Rabbits were sacrificed 1, 3, 7, 14, 21, 28, 45 days after surgery respectively. The histopathology and expressions of VEGF at different periods of the fracture healing were investigated by means of RT-PCR. Results At 28 days postoperatively, the histopathological examination showed that 8 limbs had osteal callus and 4 limbs had chondral callus at the site of osteotomy in the control group while in experimental group 6 had osteal callus and 14 chondral callus (P< 0.01). There was no significant difference between the 2 groups (P >0.05)in the expression of VEGF which increased gradually after operation and reached the summit 14 days postoperatively. Then, it decreased gradually, but still maintained a high level at 28 days postoperatively. Conclusion Seawater immersion delays the process of bone healing and may cause delayed union, but it has little impact on the expression of VEGF.