自控微动带锁髓内钉内固定对骨折愈合影响的扫描电镜观察与生化分析

目的:观察自控微动带锁髓内钉AMLN]内固定对骨折愈合的影响及机制。方法:对12只山羊两侧股骨干横断截骨,分别采用AMLN和GK钉固定,术后7、14、28、56d分批处死,行生物化学测量,扫描电镜观察。结果(1)电镜观察术后7～14d AMLN固定组骨痂丰富、层叠状有序排列,骨小梁的吸收陷窝内有胶原纤维不断形成;术后28～56d骨胶原纤维在吸收陷窝内外形成丰富,互相平行束状排列,与骨干主应力轴相一致,骨吸收和骨生成活跃,骨塑形改建迅速,哈佛氏系统结构完整,结构网架在骨质钙盐结晶沉积下十分坚韧;而GK钉固定组则无上述特征现象发生;(2)AMLN钉固定组的骨痂胶原、不溶性胶原、钙、磷含量均高于GK钉固定组(P<0.05)。结论:AMLN钉固定使骨折端局部稳定、有轴向生理性应力刺激与应力传导,增加了成骨细胞的代谢活性,使骨小梁沿压应力轴线发育,促进了骨胶原生成、骨盐的沉积及转化、骨痂的形成和强度的提高,加快了骨质重建的速度。

Observation for the Influence of the Fixation with Auto-control Micro-motion Locking Nail on the Mode of Fracture Healing

Objective:To explore the influence of auto-control micro-motion locking nail(AMLN) on the fracture healing process,and it's mechanism. Methods:Twenty-four femoral shafts of 12 goats were fractured transversely and were fixed with AMLN and GK nails respectively. The animals were killed at 1,2,4 and 8 weeks postoperat.ively,both the biochemical measurements and the scanning electro - microscopic observation in the fracture were conducted. Results: (1) The callus of AMLN group animals "were rich and ordered, The collagen fibril in bone trabecula sucking lacuna was forming continuously at one to two weeks after operation. The collagen fibril in bone trabecula sucking lacuna was rich and lined parallel according with the bony axis. The bony absorption and formation were in full swing, the bony moulding and rebuilding "were prompt, the haversion system was integrity, the bony structural net was very tenacity with bony calcium salt crystal. None above phenomenon was observed in the GK fixation group. (2) The content of the total collagen, insoluble collagen, calcium and phosphate in the experimental group fixed with AMLN were higher than that in the control group (P<0. 05) . Conclusion:The fixation of fractural end with AMLN could offer the best biomechanical environment through making fractural end stabilization, producing physical stress stimulus according to the bony trunk axis,making the metabolic activity of osteoblast enhance significantly bone trabecula growth along it' s axial line. It prompts the collagen forming, calcium salt sediment and transform and make callus forming intension increase. The substance of bone reconstructed phase speed up.