State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun, People's Republic of China.
Biomed Eng Online. 2012 Jun 18;11:31. doi: 10.1186/1475-925X-11-31.
For the treatment of low back pain, the following three scenarios of posterior lumbar interbody fusion (PLIF) were usually used, i.e., PLIF procedure with autogenous iliac bone (PAIB model), PLIF with cages made of PEEK (PCP model) or titanium (Ti) (PCT model) materiel. But the benefits or adverse effects among the three surgical scenarios were still not fully understood.
Finite element analysis (FEA), as an efficient tool for the analysis of lumbar diseases, was used to establish a three-dimensional nonlinear L1-S1 FE model (intact model) with the ligaments of solid elements. Then it was modified to simulate the three scenarios of PLIF. 10 Nm moments with 400 N preload were applied to the upper L1 vertebral body under the loading conditions of extension, flexion, lateral bending and torsion, respectively.
Different mechanical parameters were calculated to evaluate the differences among the three surgical models. The lowest stresses on the bone grafts and the greatest stresses on endplate were found in the PCT model. The PCP model obtained considerable stresses on the bone grafts and less stresses on ligaments. But the changes of stresses on the adjacent discs and endplate were minimal in the PAIB model.
The PCT model was inferior to the other two models. Both the PCP and PAIB models had their own relative merits. The findings provide theoretical basis for the choice of a suitable surgical scenario for different patients.
对于治疗下腰痛，通常采用三种后路腰椎间融合术（PLIF）的方案，即采用自体髂骨（PAIB 模型）的 PLIF 手术、采用聚醚醚酮（PEEK）（PCP 模型）或钛（Ti）（PCT 模型）材料制成的笼的 PLIF。但三种手术方案的益处或不良影响仍不完全清楚。
有限元分析（FEA）作为分析腰椎疾病的有效工具，用于建立具有固体元素的韧带的三维非线性 L1-S1 FE 模型（完整模型）。然后对其进行修改以模拟 PLIF 的三种方案。在伸展、弯曲、侧屈和扭转的加载条件下，分别在 L1 上椎体的上表面施加 10 Nm 的力矩和 400 N 的预载。
计算了不同的力学参数来评估三种手术模型之间的差异。在 PCT 模型中，骨移植物上的应力最低，终板上的应力最大。PCP 模型获得了相当大的骨移植物上的应力和较少的韧带上的应力。但是，PAIB 模型中相邻椎间盘和终板上的应力变化最小。
PCT 模型劣于其他两种模型。PCP 和 PAIB 模型各有其优缺点。研究结果为不同患者选择合适的手术方案提供了理论依据。
