持续动态压应力对实验性骨折愈合的影响

Effect of continuous dynamic compressive stress on femoral fractures healing in dogs

目的 :探讨持续动态压应力环境对实验性骨折愈合的影响及机制 .方法 :对 2 5只家犬股骨干造成双侧横断截骨 ,随机选一侧天鹅记忆接骨器 (SMC)固定 ,对侧以髓内钉固定作为对照 ,分别在术后 7,1 4 ,2 1 ,2 8和 4 9d时 ,在骨折间隙内取材 ,行组织学观察及Ⅸ型胶原和骨钙素mRNA的Northernblot杂交 .结果 :组织学观察和Northernblot结果均表明 ,SMC固定下骨折间隙内愈合组织的软骨形成速度明显快于对照组 ,软骨内成骨也得以强化 .结论

AIM: To explore the effect and mechanism of continuous dynamic pressure stress on femoral fractures healing in dogs. METHODS: Bilateral femoral of 15 adult dogs were osteotomized in the middle and then 1 femur was randomly internal fixed with swan like memory connector (SMC) while the contralateral side fixed with Kuntscher intramedullary nails. Five animals in each group were sacrificed at 7, 14, 21, 28, 49 d after operation. Samples from the fracture gaps were obtained and histological and molecular biological techniques (expression of the mRNA of the cartilage specific collagen IX and osteocalcina marker for mature osteoblasts) were employed. RESULTS: In terms of histology and molecular biology, the chondrogenesis in the fracture gap continued for shorter period and the enchondral ossificassion were strengthened in fractures fixed with SMC. CONCLUSION: The persistent dynamic longitudinal pressure stress produced by SMC may contribute to the process of healing of long bone.