Abstract Cage subsidence in transforaminal lumbar interbody fusion (TLIF) is one of the concerns. The objective was to numerically assess the resulting segmental lumbar lordosis (SLL) and stresses at the bone-cage interface as functions of cage height (8- vs. 10-mm) and cage placement (oblique asymmetric, vs. anterior symmetric) for normal and osteoporotic bone quality. A L4-L5 detailed finite element model of TLIF was subjected to the functional loadings of 10 Nm in the physiological planes after the application of a 400 N follower-load. The SLL was increased by 0.9° (11%) and 1.0° (13%), respectively in oblique asymmetric and anterior symmetric cage placement with 8-mm height; they were 1.4° (18%) and 1.7° (21%) for the 10-mm cage. The maximum stresses at the cage-bone interface, in normal bone model, were increased up to 16% and 41% with the 10-mm cage and asymmetric oblique placement, respectively, and they increased up to 16% and 43% in osteoporotic bone model. The greater cage resulted to a higher simulated SLL. Oblique asymmetric placement and the use of a greater cage may increase the risk of cage subsidence. Due to the lower mechanical strength of osteoporotic bone, the risk of cage subsidence should be higher.

中文翻译：

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椎间孔腰椎椎间融合术中不同笼高度和不同位置的节段性腰椎前凸和笼下沉风险的生物力学分析

摘要 经椎间孔腰椎椎间融合（TLIF）中的笼子下沉是关注的问题之一。目的是在数值上评估所产生的节段性腰椎前凸 (SLL) 和骨-笼接口处的应力，作为正常情况下骨笼高度（8 对 10 毫米）和笼放置（倾斜不对称，对前对称）的函数和骨质疏松的骨质量。在应用 400 N 跟随负载后，TLIF 的 L4-L5 详细有限元模型在生理平面中承受 10 Nm 的功能负载。SLL 分别增加了 0.9° (11%) 和 1.0° (13%)，在 8 mm 高度的倾斜不对称和前对称笼放置中；对于 10 毫米笼，它们是 1.4° (18%) 和 1.7° (21%)。笼骨界面处的最大应力，在正常骨骼模型中，10 毫米笼和不对称斜置分别增加了 16% 和 41%，在骨质疏松骨模型中增加了 16% 和 43%。更大的笼子导致更高的模拟 SLL。倾斜的不对称放置和使用更大的笼子可能会增加笼子下沉的风险。由于骨质疏松骨的机械强度较低，笼子下沉的风险应该更高。