动力加压髋螺钉对股骨上段生物力学特征性的影响

目的：探讨股骨上端骨折，以动力加压髋螺钉进行骨固定治疗，骨折愈合后，取出动力加压髋螺钉以后的股骨上段与完整的股骨上段的生物力学特性相比较，为临床内固定取出术后功能锻炼的强度提供量化依据。方法：收集8具新鲜尸体股骨标本进行实验应力分析，分别测定完整股骨上段和动力加压髋螺钉取出后股骨上段的力学特性改变。结果：动力加压髋螺钉取出术后股骨上段的力学特性与完整股骨上段的力学特性相比有显著的差异（P＜0．01）。结论：股骨上端骨折如果以动力加压髋螺钉为治疗手段，在骨折愈合取出内固定后，功能锻炼只能控制在慢速步行水平，不能进行奔跑、跳跃等活动，以防止再骨折等并发症的发生。

Effects of biomechanical characteristics of the proximal femurs on dynamic hip screws

Objective: Proximal femoral fractures were treated with internal fixation of dynamic hip screws. The biomechanical changes of proximal femurs without internal fixations after the fracture union were investigated by comparing with intract femurs. The purpose of this study is to get quantitative proofs of exercise intensity after internal fixation being taken out. Methods: The proximal femurs fo eight fresh cadavers were used in stress analysis. The biomechanical characters of intact proximal femurs and proximal femurs removed dynamic hip screws were determined. Results: The biomechanical characters of intact proximal femurs and proxidmal femurs without dynamic hip screws have statistically differences (P< 0. 01). Conclusion: proximal femur fractures were treated with dynamic hip screws. After fracture healing and internal fixation being taken out, the biomechanical intensity decreases only to support the movement of walking, not running or jumping. Otherwise the complication of refracture will be appearing.