脊柱颈胸结合部C5~T2三维有限元建模与验证

目的基于CT图像数据建立人体脊柱颈胸结合部C5~T2的三维有限元模型,并验证模型的正确性和有效性。方法采用Mimics、Geomagic和Hypermesh软件对人体脊柱颈胸结合部C5~T2椎体进行三维重建、模型修复和有限元前处理,对模型顶面施加±0.5、1、1.5、2 N·m扭矩,用于模拟人体前屈和后伸活动时所产生的载荷作用,使用ANSYS软件计算脊柱颈胸结合部C5~T2节段在前屈和后伸承受扭矩载荷作用时的关节活动度(range of motion,ROM),将计算结果与前人研究结果进行对比分析。结果人体脊柱颈胸结合部C5~T2三维模型中C5~6、C6~7、C7~T1和T1~2各节段椎体在1 N·m载荷作用下,前屈时ROM分别为4.30°、3.21°、1.66°和1.41°,后伸时ROM分别为3.47°、2.86°、0.96°和0.92°。前屈时最大应力出现在椎体前缘,后伸时椎体后缘出现较大应力。ROM和应力分布的趋势与前人研究结果相一致。结论建立的脊柱颈胸结合部三维模型精确逼真,符合脊柱颈胸结合部的生物力学特性,模拟结果可为临床病理研究和颈胸部手术术式的评价提供理论依据。

Establishment and validation for a 3D finite element model of cervicothoracic junction C5-T2

Objective To establish a 3D finite element model of cervicothoracic spinal segments C5-T2 based on CT images and test its validity and effectiveness. Methods By using the Mimics, Geomagic and Hypermesh software, the 3D model of cervicothoracic spinal segments C5-T2 was reconstructed, repaired and pre-processed. Moment of ±0.5, 1, 1.5, 2 N?m were applied on top of the model to simulate loads produced during the flexion and extension movement of human body. The range of motion (ROM) of the segments C5-T2 during flexion and extension was calculated by ANSYS, and the reliability of the model was verified by comparing the experimental results in the previous literature with the finite element analysis results obtained in this study. Results Under the moment of 1 N?m, the ROMs of C5-6, C6-7, C7-T1 and T1-2 during flexion were 4.30°,3.21°,1.66° and 1.41°, and those during extension were 3.47°, 2.86°, 0.96° and 0.92°, respectively. The maximum stress during flexion appeared on the front of the vertebral body, while that during extension appeared on the back of the vertebral body. The trends of ROM and stress distributions were consistent with results reported in the previous literature. Conclusions The 3D model established in this study is accurate and realistic, and conforms to biomechanical properties of the cervicothoracic spine. The simulation results can be further used to explore clinical pathology of the spine and provide theoretical references for evaluation on cervicothoracic spine surgery.