股骨粉碎性骨折动静力型髓内钉固定的力学特点及意义

Biomechanics characteristics of comminuted femoral fracture fixed by dynamic or static interlocking intramedullary nailing and its clinical value s

目的:分析自行设计动力型带锁髓内钉和目前常用静力型带锁髓内钉固定股骨粉碎性骨折的力学特点及临床意义。方法:将动力型带锁髓内钉与意大利产Orthofix静力型带锁髓内钉固定股骨粉碎性骨折后进行纵向加压力学实验比较。结果:(1)静力型固定股骨粉碎性骨折能够提供足够轴向和旋转稳定性,但由于应力遮挡,早期负重易发生锁钉断钉及骨折延迟愈合或不愈合。(2)动力型固定股骨粉碎性骨折有退钉、骨碎块散裂、肢体缩短的影响,但足以维持骨折的稳定性。结论:股骨粉碎性骨折为动力型带锁髓内钉扩大范围的适应症。

Objective: To compare the biomechanics character istics between dynamic interlocking intramedullary nailing designed by ourselves and static interlocking intramedullary nailing used commonly to fix the comminu ted femoral fracture, and the clinical values of the dynamic interlocking intram edullary nailing. Methods: The longitudinal compression biom echanics contrast tests were performed at the comminuted fractures of fresh femo ral bones from the dead human bodies fixed by the dynamic interlocking intramedu llary nailing or static interlocking intramedullary nailing(Orthofix, made in It aly). Results: The comminuted femoral fracture fixed by the static interlocking intramedullary nailing could provide enough stabilization at longitudinal direction and rotation, but locking nailing broke caused by this f ixation if the fixed femoral bone bore weights at early phase due to stress shie lding, which would result in fracture delayed union or even nonunion The comminu ted femoral fracture fixed by dynamic nailing had the inclination to cause nail retreated, fracture fragments separated and leg shorten, but this fixation could provide sufficient fracture stabilization. Conclusion: Comm inuted femoral fracture is another indication fixed by dynamic interlocking intr amedullary nailing.