Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi Prefecture, Japan.
Engineering Center for Orthopaedic Research Excellence (E-CORE), Departments of Bioengineering and Orthopaedics, The University of Toledo, Toledo, Ohio, USA.
World Neurosurg. 2022 Aug;164:e358-e366. doi: 10.1016/j.wneu.2022.04.112. Epub 2022 May 2.
Soft tissue cervical spine injury (CSI) has the possibility of causing cervical segmental instability, which can lead to spinal cord injury. There is a lack of certainty in assessing whether soft tissue CSI is unstable or not. This biomechanical study aimed to investigate the risk factors of soft tissue CSI.
A 3-dimensional finite element model of the ligamentous cervical spine (C2-C7) was created from medical images. Three soft tissue injury models were simulated at C4-C5: 1) posterior ligament complex (PLC) injury, 2) intervertebral disk (ID) with anterior longitudinal ligament injury (IDI), and 3) anterior longitudinal ligament, PLC, and ID injury (API) model. Pure moment with compressive follower load was applied, and the range of motion, annular stress, nucleus stress, and facet forces were analyzed.
For the IDI and API models, the range of motion increased at the injury level in extension (by 101%) and left/right axial rotations (>30%) compared with the intact model. The IDI and API models showed an increase of >50% in annular and nucleus stresses at the injury level in extension and left/right rotations compared with the intact model. The PLC injury showed similar stresses as the intact model except for flexion. The facet contact forces of IDI and API models increased more than 100% compared with other models in all motions.
In CSI, all soft tissues have a key role in stabilizing cervical spine, but ID is the most important component of all.
软组织颈椎损伤（CSI）有可能导致颈椎节段不稳定，从而导致脊髓损伤。评估软组织 CSI 是否不稳定的确定性不足。本生物力学研究旨在探讨软组织 CSI 的危险因素。
从医学图像创建韧带颈椎（C2-C7）的三维有限元模型。在 C4-C5 模拟了三种软组织损伤模型：1）后韧带复合体（PLC）损伤，2）椎间盘（ID）伴前纵韧带损伤（IDI），3）前纵韧带、PLC 和 ID 损伤（API）模型。施加纯矩压缩随动载荷，分析运动范围、环形应力、核应力和小关节力。
与完整模型相比，IDI 和 API 模型在伸展时损伤水平的运动范围增加（增加 101%），左侧/右侧轴向旋转增加（增加>30%）。IDI 和 API 模型在伸展和左右旋转时，损伤水平的环形和核应力增加>50%，与完整模型相比。PLC 损伤在除了屈曲之外的其他运动中表现出与完整模型相似的应力。IDI 和 API 模型的小关节接触力在所有运动中比其他模型增加超过 100%。
在 CSI 中，所有软组织在稳定颈椎方面都起着关键作用，但 ID 是所有软组织中最重要的组成部分。
