PDF(Pubmed)
Abstract：
Background and Objectives: Spine surgery using a percutaneous pedicle screw placement (PPSP) is widely implemented for spinal trauma. However, percutaneous systems have been reported to have weak screw-rod connections. In this study, conventional open and percutaneous systems were biomechanically evaluated and compared. Material and Methods: The experiments were performed in two stages: the first stage was a break test, whereas the second stage was a fatigue test. Four systems were used for the experiments. System 1 was intended for conventional open surgery (titanium rod with a 6.0 mm diameter, using a clamp connecting mechanism). System 2 was a percutaneous pedicle screw (PPS) system for trauma (titanium alloy rod with a 6.0 mm diameter, using ball ring connections). System 3 was a PPS system for trauma (cobalt-chromium alloy rod with a 6.0 mm diameter, using sagittal adjusting screw connections). System 4 was a general-purpose PPS system (titanium alloy rod with a 5.5 mm diameter, using a mechanism where the adapter in the head holds down the screw). Results: Stiffness values of 54.8 N/mm, 43.1 N/mm, 90.9 N/mm, and 39.3 N/mm were reported for systems 1, 2, 3, and 4, respectively. The average number of load cycles in the fatigue test was 134,393, 40,980, 1,550,389, and 147,724 for systems 1 to 4, respectively. At the end of the test, the displacements were 0.2 mm, 16.9 mm, 1.2 mm, and 8.6 mm, respectively. System 1, with a locking mechanism, showed the least displacement at the end of the test. Conclusion: A few PPS systems showed better results in terms on stiffness and life than the open system. The experiments showed that mechanical strength varies depending on the spinal implant. The experiments conducted are essential and significant to provide the mechanical strength required for surgical reconstruction.
摘要：
背景和目的：经皮椎弓根螺钉置入（PPSP）的脊柱手术已广泛用于脊柱创伤。然而,据报道，经皮系统具有弱的螺杆连接。在这项研究中,对常规开放和经皮系统进行生物力学评估和比较。材料和方法:实验分两个阶段进行:第一阶段是断裂试验,而第二阶段是疲劳试验。四个系统用于实验。系统1旨在用于常规的开放手术（直径为6.0mm的钛棒，使用夹具连接机构)。系统2是用于创伤的经皮椎弓根螺钉（PPS）系统（直径为6.0mm的钛合金棒，使用球环连接)。系统3是用于创伤的PPS系统（直径为6.0mm的钴铬合金棒，使用矢状调节螺钉连接)。系统4是通用的PPS系统（直径为5.5mm的钛合金棒，使用机头中的适配器压住螺钉的机构)。结果：刚度值为54.8N/mm，43.1N/mm,90.9N/mm,系统1、2、3和4分别报告了39.3N/mm。对于系统1至4，疲劳测试中的平均载荷循环次数分别为134,393、40,980、1,550,389和147,724。在测试结束时,位移为0.2毫米，16.9mm,1.2mm,和8.6毫米，分别。系统1，带有锁定机构，在测试结束时显示出最小的位移。结论：一些PPS系统在刚度和寿命方面比开放系统表现出更好的结果。实验表明，机械强度随脊柱植入物的不同而变化。进行的实验对于提供手术重建所需的机械强度至关重要。
