Wang Kuan, Deng Zhen, Wang Huihao, Li Zhengyan, Zhan Hongsheng, Niu Wenxin
Shi's Center of Orthopedics and Traumatology, Shuguang Hospital Affiliated to Shanghai University of TCM, Shanghai 201203, China; Institute of Traumatology, Shanghai Academy of TCM, Shanghai 201203, China.
Shi's Center of Orthopedics and Traumatology, Shuguang Hospital Affiliated to Shanghai University of TCM, Shanghai 201203, China; Institute of Traumatology, Shanghai Academy of TCM, Shanghai 201203, China.
J Mech Behav Biomed Mater. 2017 Aug;72:129-137. doi: 10.1016/j.jmbbm.2017.05.005. Epub 2017 May 3.
The ligaments of the cervical spine each play a critical role in maintaining stability. Large variations in the mechanical behavior of each ligament have been reported, but it remains unclear how these variations influence cervical biomechanics. The objective of this study was to investigate the mechanical response of the cervical spine to variations in the properties of each cervical ligament. A finite element model of the C5-C6 spine was constructed with the average material properties. The stiffness of each ligament was then changed in turn by increasing or decreasing it per its designated maximum or minimum stiffness. The range of motion (ROM) and intradiscal pressure (IDP) were calculated and compared among the different models under pure moments. The results showed that the capsular ligament with the greatest stiffness caused a lower ROM in all anatomical planes. Varying the stiffness of the anterior longitudinal ligament had the greatest influence on ROM in extension, while the interspinous ligament was the most influential in flexion. During lateral bending or axial rotation, the capsular ligament with the minimum stiffness resulted in a higher IDP, while the capsular ligament with the maximum stiffness resulted in a lower IDP. Varying the capsular ligament stiffness had the greatest role on the C5-C6 ROM and therefore care must be taken to assign appropriate material properties. This study showed a less influence on the intervertebral disc with smaller ROM, especially when the ligaments were relaxed. This suggested that the control of the neck posture may be beneficial for patients with a degenerated cervical spine.
颈椎韧带在维持稳定性方面各自发挥着关键作用。已有报道称各韧带的力学行为存在很大差异，但这些差异如何影响颈椎生物力学仍不清楚。本研究的目的是调查颈椎对各颈椎韧带特性变化的力学反应。构建了具有平均材料特性的C5 - C6脊柱有限元模型。然后通过根据各韧带指定的最大或最小刚度增加或降低其刚度，依次改变每条韧带的刚度。计算并比较了不同模型在纯力矩作用下的运动范围（ROM）和椎间盘内压力（IDP）。结果表明，刚度最大的关节囊韧带在所有解剖平面上导致的ROM较低。改变前纵韧带的刚度对伸展时的ROM影响最大，而棘间韧带在屈曲时影响最大。在侧屈或轴向旋转过程中，刚度最小的关节囊韧带导致IDP较高，而刚度最大的关节囊韧带导致IDP较低。改变关节囊韧带刚度对C5 - C6的ROM影响最大，因此必须谨慎赋予适当的材料特性。本研究表明，ROM较小时对椎间盘的影响较小，尤其是当韧带松弛时。这表明控制颈部姿势可能对颈椎退变患者有益。
