Li Xin-Feng, Dai Li-Yang
Department of Orthopaedic Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, Peoples Republic of China/
Spine (Phila Pa 1976). 2009 May 15;34(11):1140-7. doi: 10.1097/BRS.0b013e31819e2af1.
A three-dimensional finite element investigation.
To create a three-dimensional finite element model of the cervical spinal cord enlargement and to simulate a hyperextension injury of the cervical cord.
Experimental studies are difficult to simulate the complex mechanism of spinal cord injuries. The introduction of three-dimensional modeling technique into neurotrauma studies is essential to further understand mechanical behavior of the nerve tissue during traumatic injuries.
Geometrical reconstruction of cervical spinal cord enlargement was developed based on the morphologic features of each segment of the fresh human cervical cord. After the validation of the model, the pinching condition in the hyperextension injuries was simulated with compressive and extension forces applied on the cervical enlargement model. The average von Mises stress of the 9 anatomic regions, such as anterior funiculus, lateral part of the lateral funiculus, medial part of the lateral funiculus, lateral part of the posterior funiculus, medial part of the posterior funiculus, anterior horn, the bottom of anterior horn, the apex of posterior horn, the cervix cornu posterioris, and caput cornu posterioris was recorded.
The force-displacement response of the spinal cord under compression and axial tension loading was close to the experimental results reported in the literature. The stress distribution of the spinal cord according to the numerical simulation and the morphologic features of the in vivo experiment were also in close agreement. Hyperextension injury simulation showed high localized stress at the anterior and posterior horn in the gray matter.
The finite element method as a three-dimensional modeling technique can improve the understanding of the biomechanical behavior of the spinal cord. The results of hyperextension injury simulation of the cervical spinal cord probably account for the predominance of the hand weakness in patients with central cord injury.
三维有限元研究。
创建颈脊髓膨大的三维有限元模型并模拟颈髓的过伸损伤。
实验研究难以模拟脊髓损伤的复杂机制。将三维建模技术引入神经创伤研究对于进一步了解创伤性损伤期间神经组织的力学行为至关重要。
根据新鲜人颈髓各节段的形态特征对颈脊髓膨大进行几何重建。模型验证后，通过对颈膨大模型施加压缩力和伸展力来模拟过伸损伤中的挤压情况。记录9个解剖区域的平均冯·米塞斯应力，这些区域包括前索、外侧索外侧部、外侧索内侧部、后索外侧部、后索内侧部、前角、前角底部、后角尖、后角颈部和后角头部。
脊髓在压缩和轴向拉伸载荷下的力-位移响应与文献报道的实验结果相近。根据数值模拟得到的脊髓应力分布与体内实验的形态学特征也密切相符。过伸损伤模拟显示灰质的前角和后角有高度局部化应力。
有限元方法作为一种三维建模技术可增进对脊髓生物力学行为的理解。颈脊髓过伸损伤模拟结果可能解释了中央脊髓损伤患者手部无力占主导的原因。
