目的对自行设计的ZH椎弓根内固定器治疗胸腰椎骨折进行力学测试,为临床应用提供生物力学依据。方法取9具新鲜的成人尸体胸腰椎脊柱标本,采用Panjabi方法制作损伤模型,用ZH椎弓根内固定器、Dick钉、Steffee钢板三种内固定方法分组固定后,分别进行载荷-应变、椎体强度、位移、扭转强度、稳定性与刚度及胸腰椎极限承载能力等生物力学测试。结果经生物力学测试,椎体应变:ZH内固定器组明显小于Dick钉组和Steffee钢板组,A点应变分别相差7.2%、14%(P<0.05),B点相差17%、28%(P<0.05);椎体强度:ZH内固定器组与两对照组相比A点应力减小7%与14%(P<0.05),B点应力减小17%和29%(P<0.05);纵向位移ZH内固定器组比两对照组分别减少24%和33%(P<0.05),水平位移减少40%和55%(P<0.05)。结论ZH椎弓根内固定器生物力学性能优良,临床可推广使用。

Objective To provide the biomechanical basis for ZH transpedicular internal fixator used in thoracolumbarfracture treatment. Methods Trauma models were made from 9 fresh cadavers by Panjabi method and divided into 3 groupswith ZH transpedicular internal fixator, Dick screw and Steffee plate, respectively. To test their biomechanical capability inload-responsive change、centrum intensity、displacement、torsion intensity、stability, rigidity and ultimate strength.Results The results of the test showed that ZH transpedicular internal fixator was much better than the other two oneswith: load-responsive change was much less than that of Dick screw and Steffee plate by 7.2% and 14% at Point A andby 17% and 28% at Point B; Centrum intensity: stress decreased by 7% and 14% at Point A, while at Point B by 17% and29%; The displacement decreased by 24% and 33% vertically, and 40% and 55% horizontally. Conclusions The ZHtranspedicular internal fixator is suitable to popularized in clinic application with its better biomechanical capability.