新型腰椎后路经皮动态内固定系统的力学测试

Mechanical tests of a novel percutaneous posterior lumbar dynamic stabilization system

[目的]对一种新型的腰椎后路可经皮微创置入的动态内固定系统的动态棒进行力学测试,探讨其临床应用的理论基础。[方法]提出新型动态内固定棒的设计思路,委托器械公司加工制造样品,进行新型腰椎后路微创动态内固定棒与坚强内固定棒的力学测试,分组进行抗压、拉伸、扭转试验(包括正转与反转),记录微创动态内固定棒与坚强内固定棒在不同程度载荷下的位移程度、扭转程度,比较其差异。[结果]加载生理负荷范围下,微创动态内固定棒的屈曲活动度、位移活动度及扭转活动度分别为15°、0.48 mm及6°,与坚强固定棒相比均存在显著差异,有统计学意义(P<0.05)。[结论]该系统符合微创与动态固定理念,并具有良好的稳定性,同时可部分保留固定节段的活动度。

[Objective] To test the mechanical characteristics of a new percutaneous minimally invasive posterior lumbar dynamic stabilization system for building foundation of its clinical application. [Methods] Based on the design ideas and blueprint supplied by the authors, samples of a new percutaneous minimally invasive posterior lumbar dynamic stabilization system were manufactured by Zhejiang Guangci Medical Device Co., Ltd. Afterward, the dynamic rods of the system were me- chanically assessed under different loadings including compressive, tensile, forward and reverse torsive tests, comparing with the traditional rigid rod. [ Results] Under the physical loads, the dynamic rods had 15° of flexion under the compression, 0.48 mm of elongation under the tension and 6.11° of rotation under the torsion, which were statistically different with the traditional rigid rods. [ Conclusion] To be consistent with the concept of minimally invasive and dynamic stabilization, this newly developed system has sufficient stabilizing effect and retains a proper motion.