新型微创椎弓根钉-板固定系统的生物力学测试

发布时间：2018-09-11 10:31

【摘要】：目的 :评估新型微创椎弓根钉-板内固定系统的生物力学强度。方法:根据美国材料测试协会(ASTM)标准构建单钉-棒测试组件,在万能材料试验机上分别对微创椎弓根钉-板、单向椎弓根钉-棒和万向椎弓根钉-棒组件进行生物力学强度测试。测试内容包括静态侧压测试和疲劳测试。在静态侧压测试中使用6套组件,记录组件屈服载荷、屈曲刚度以及失效模式。在疲劳测试中记录完成250万次循环负荷的最大应力数值。结果:微创椎弓根钉-板组件的屈服载荷和屈曲刚度显著低于单向椎弓根钉-棒组件(834.6±74.5N vs 1087.7±59.0N,218.1±22.4N vs 300.0±14.9N,P0.001)。微创椎弓根钉板组件的屈服载荷与万向椎弓根钉-棒组件比较无显著性差异(834.6±74.5N vs 762.8±88.6N,P=0.118);而钉-板组件的刚度显著低于万向钉-棒组件(218.1±22.4N/mm vs 389.5±37.2N/mm,P0.001)。单向椎弓根钉-棒组件的失败模式为连接棒发生塑性形变,万向椎弓根钉-棒组件为"球窝偶联"结构失效,微创椎弓根钉-板组件为钛板的塑性形变和钉-板连接部位失效。在250万次动态侧压疲劳测试中,单向椎弓根钉-棒组件、微创椎弓根钉-板组件和万向椎弓根钉-棒组件分别在450N、450N和350N循环载荷下完成测试。结论:新型微创椎弓根钉-板内固定系统可耐受250万次450N循环载荷作用,同时具有高屈服载荷和低屈曲刚度的特点。
[Abstract]:Objective: to evaluate the biomechanical strength of a new minimally invasive pedicle screw-plate fixation system. Methods: according to the (ASTM) standard of the American Association of material testing, a single nail-bar test module was constructed, and the minimally invasive pedicle screw-plate was performed on a universal material testing machine. The biomechanical strength of unidirectional pedicle screw-rod and universal pedicle screw-rod assembly were measured. The test includes static lateral pressure test and fatigue test. Six sets of components were used to record the yield load, buckling stiffness and failure mode. The maximum stress values of 2.5 million cycles were recorded in fatigue test. Results: the yield load and buckling stiffness of minimally invasive pedicle screw plate assembly were significantly lower than that of unidirectional pedicle screw rod assembly (834.6 卤74.5 N vs 1087.7 卤59.0 N vs 218.1 卤22.4 N vs 300.0 卤14.9 Nu P0.001). There was no significant difference between the yield load of the minimally invasive pedicle screw plate assembly and that of the universal pedicle screw rod assembly (834.6 卤74.5 N vs 762.8 卤88.6 NV P0. 118), but the stiffness of the nail-plate assembly was significantly lower than that of the universal screw rod assembly (218.1 卤22.4N/mm vs 389.5 卤37.2 NmmP0.001). The failure mode of unidirectional pedicle screw-rod assembly is plastic deformation of the connecting rod, the failure of the universal pedicle screw-rod assembly is "ball socket coupling" structure, and the minimally invasive pedicle screw-plate assembly is the plastic deformation of titanium plate and the failure of nail-plate connection In 2.5 million dynamic lateral compression fatigue tests, the unidirectional pedicle screw-rod assembly, the minimally invasive pedicle screw-plate assembly and the universal pedicle screw-bar assembly were tested under 450 N and 350 N cyclic loads, respectively. Conclusion: the new minimally invasive pedicle screw plate fixation system can withstand 2.5 million times of 450N cyclic loading and has the characteristics of high yield load and low buckling stiffness.
【作者单位】：第三军医大学附属新桥医院骨科;
【基金】：国家科技攻关计划(2012BAI14B00) 重庆市科委重大专项资助项目(CSTC2012gg_yyjs B10012)
【分类号】：R318.01;R687.3

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