天鹅记忆接骨器对实验性骨折愈合时骨桥素和骨连接素mRNA表达的影响

目的:探讨天鹅记忆接骨器对实验性骨折愈合中骨桥素和骨连接素mRNA表达的影响.方法:30只新西兰兔双侧肱骨干横断截骨,随机选一侧以天鹅记忆接骨器内固定作为实验组,对侧以4孔加压钢板固定作为对照组.分别于术后第2、7、14、28、56天时,在骨折间隙取材,行组织学观察及半定量RT-PCR检测骨桥素和骨连接素mRNA的表达.结果:实验组骨折间隙软骨内成骨和编织骨向板层骨的改建均早于对照组;相应地,实验组的骨桥素和骨连接素mRNA分别在术后第14天和28天时达峰值,早于对照组,且其愈合进程也明显提前.结论:天鹅记忆接骨器产生的持续动态压应力可能促进了骨折愈合.

Influence of Swan-like memory connector on osteopontin and osteonectin mRNA expression during experimental fracture healing

Objective:To explore the effect and mechanism of continuous dynamic pressure stress, which is produced by Swan-like shape memory connector(SMC), on osteopontin and osteonectin mRNA expression during experimental fracture healing.Methods: Bilateral humeral diaphyses of 30 adult rabbits were osteotomized in the middle and then 1 humerus was randomly chosen for internal fixation with SMC and the contralateral side was fixed with 4-hole dynamic compression plate(DCP). Six animals were sacrificed at 2, 7, 14, 28 and 56 days after operation and samples from the fracture gaps were obtained. Histological observation and RT-PCR were employed to study the expression of osteopontin and osteonectin mRNA.Results: In terms of histology, the endochondral bone formation and callus remodelling took place earlier in fractures fixed with SMC than with DCP. Osteopontin and osteonectin mRNA expression levels peaked at 14 and 28 days after the fracture, respectively. There was a delay in the increase and decrease of osteopontin and osteonectin mRNA in DCP fixed cases. Conclusion: The persistent dynamic longitudinal pressure stress produced by SMC may promote the healing process of long bones.