PURPOSE To compare the effect of conventional pedicle screw (CPS) and cement-augmented pedicle screw instrumentation (CAPSI) on adjacent segment degeneration (ASD). METHODS A normal male volunteer without a history of spinal disease was selected, lumbar CT data was collected, an intact L3-S1 three-dimensional finite element model was created by software including Mimics, Geomagic, and SolidWorks, and the fixation methods were performed accordingly. A common pedicle screw model and a cement-augmented pedicle screw model of L4-L5 with fusion and internal fixation were constructed. With ANSYS Workbench 17.0, a 500 N load was applied to the upper surface of L3 to simulate the weight of a human body, and a 7.5 N m moment was applied at the neutral point to simulate flexion, extension, left/right bending, left/right rotation of the spine. The peak von Mises stress of intervertebral disc and the range of motion (ROM) on the adjacent segments (L3-4 and L5-S1) were compared. RESULTS The validity of the intact model shows that the ROM of the model is similar to that of a cadaveric study. Compared with the intact model, CPS model and CAPSI model in all motion patterns increased the ROM of adjacent segments. The intervertebral disc stress and the ROM of adjacent segments were found to be higher in the CAPSI model than in the CPS model, especially in L3-4. CONCLUSION In general, the biomechanical analysis of an osteoporotic lumbar spine showed that both CPS and CAPSI can increase the ROM and disc stresses of osteoporotic lumbar models, and compared with CPS, CAPSI is more likely to increase the potential risk of adjacent segment degeneration.

中文翻译：

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在相邻节段的骨质疏松性腰s部脊柱中使用水泥增强的椎弓根螺钉器械的影响：3D有限元研究。

目的比较传统椎弓根螺钉（CPS）和水泥增强椎弓根螺钉器械（CAPSI）对邻近节段退变（ASD）的影响。方法选择无脊椎病史的正常男性志愿者，收集腰部CT数据，利用Mimics，Geomagic和SolidWorks等软件创建完整的L3-S1三维有限元模型，并据此进行固定方法。建立了融合和内固定的L4-L5椎弓根螺钉模型和水泥增强椎弓根螺钉模型。使用ANSYS Workbench 17.0，在L3的上表面施加500 N的载荷以模拟人体的重量，并在中性点施加7.5 N m的力矩以模拟弯曲，伸展，向左/向右弯曲，向左/向右旋转脊椎。比较椎间盘的von Mises峰值应力和相邻节段（L3-4和L5-S1）上的运动范围（ROM）。结果完整模型的有效性表明，该模型的ROM与尸体研究的ROM相似。与完整模型相比，所有运动模式下的CPS模型和CAPSI模型都增加了相邻段的ROM。发现在CAPSI模型中，椎间盘应力和相邻节段的ROM高于CPS模型，尤其是在L3-4中。结论总体而言，骨质疏松性腰椎的生物力学分析表明，CPS和CAPSI均可增加骨质疏松性腰椎模型的ROM和椎间盘应力，与CPS相比，CAPSI更有可能增加相邻节段变性的潜在风险。