Abstract To analyze the biomechanical stability of a redesigned cage, a new lateral plate and the effect of length of cage in CLIF, an L4-L5 finite element model was performed. Six different internal fixation methods were designed and operated under six conditions (Stand-alone CLIF; CLIF with unilateral pedicle screws (CLIF + UPS); CLIF with bilateral pedicle screws (CLIF + BPS); CLIF with lateral plate (CLIF + LP); CLIF with lateral plate and unilateral pedicle screws (CLIF + LP + UPS); CLIF with lateral plate and bilateral pedicle screws (CLIF + LP + BPS)). Ranges of motion (ROM) and stress distribution were evaluated. The effect of the length of cage was analyzed. The ROMs of stand-alone CLIF group and other internal fixation groups were decreased by >90% compared with the intact group. The CLIF + LP + BPS group has the minimum ROM. The CLIF + LP group has smaller ROM than stand-alone group. The stand-alone group has the minimum stress except for extension condition. The CLIF + LP model has less ROM, but a greater stress load was observed in the lateral plate. As for the length of cage, the largest stress is located at the junction between cage and distal end plate, especially in the epiphyseal ring and cortical compact. We conduct a new ‘cylinder wall theory’ that the cage should be placed to cover the epiphyseal ring. We recommend the length of cage should cover the epiphyseal ring to reduce the subsidence of cage.

中文翻译：

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改良腰椎椎间融合器的生物力学研究——椎间孔横向椎间融合术（CLIF）：三维有限元分析

摘要 为了分析CLIF中重新设计的笼子、新侧板的生物力学稳定性以及笼子长度的影响，建立了L4-L5有限元模型。设计了六种不同的内固定方法并在六种情况下操作（独立CLIF；CLIF带单侧椎弓根螺钉（CLIF+UPS）；CLIF带双侧椎弓根螺钉（CLIF+BPS）；CLIF带侧板（CLIF+LP）； CLIF 带侧板和单侧椎弓根螺钉（CLIF + LP + UPS）；CLIF 带侧板和双侧椎弓根螺钉（CLIF + LP + BPS））。评估了运动范围 (ROM) 和应力分布。分析了笼子长度的影响。与完整组相比，独立CLIF组和其他内固定组的ROM下降> 90％。CLIF + LP + BPS 组具有最小 ROM。CLIF + LP 组的 ROM 比独立组小。单机组除伸展条件外应力最小。CLIF + LP 模型具有较小的 ROM，但在侧板中观察到更大的应力载荷。至于笼的长度，最大的应力位于笼与远端板的交界处，尤其是骨骺环和皮质致密处。我们进行了一个新的“圆柱壁理论”，即笼子的放置应覆盖骨骺环。我们建议笼子的长度应覆盖骨骺环以减少笼子的下沉。最大的应力位于笼和远端板的交界处，特别是在骨骺环和皮质致密处。我们进行了一种新的“圆柱壁理论”，即笼子应放置以覆盖骨骺环。我们建议笼子的长度应覆盖骨骺环以减少笼子的下沉。最大的应力位于笼和远端板的交界处，特别是在骨骺环和皮质致密处。我们进行了一个新的“圆柱壁理论”，即笼子的放置应覆盖骨骺环。我们建议笼子的长度应覆盖骨骺环以减少笼子的下沉。