Beauséjour Marie-Hélène, Wagnac Eric, Arnoux Pierre-Jean, Thiong Jean-Marc Mac, Petit Yvan
Research Center, Hôpital du Sacré-Coeur de Montréal, International Laboratory on Spine Imaging and Biomechanics, Laboratoire de Biomécanique Appliquée-Université Gustave-Eiffel, Aix-Marseille Université, Department of Mechanical Engineering, École de technologie supérieure, 1100, rue Notre-Dame Ouest, Montreal, QC H3C 1K3, Canada.
Research Center, Hôpital du Sacré-Coeur de Montréal, International Laboratory on Spine Imaging and Biomechanics, Department of Mechanical Engineering, École de technologie supérieure, 1100, rue Notre-Dame Ouest, Montreal, QC H3C 1K3, Canada.
J Biomech Eng. 2022 Jan 1;144(1). doi: 10.1115/1.4052003.
Flexion-distraction injuries frequently cause traumatic cervical spinal cord injury (SCI). Post-traumatic instability can cause aggravation of the secondary SCI during patient care. However, there is little information on how the pattern of disco-ligamentous injury affects the SCI severity and mechanism. This study objective was to analyze how posterior disco-ligamentous injuries affect spinal cord compression and stress and strain patterns in the spinal cord during post-traumatic flexion and extension. A cervical spine finite element model including the spinal cord was used and different combinations of partial or complete intervertebral disc (IVD) rupture and disruption of various posterior ligaments were modeled at C4-C5, C5-C6, or C6-C7. In flexion, complete IVD rupture combined with posterior ligamentous complex rupture was the most severe injury leading to the highest von Mises stress (47-66 kPa), principal strains p1 (0.32-0.41 in white matter) and p3 (-0.78 to -0.96 in white matter) in the spinal cord and the highest spinal cord compression (35-48%). The main post-trauma SCI mechanism was identified as the compression of the anterior white matter at the injured level combined with distraction of the posterior spinal cord during flexion. There was also a concentration of the maximum stresses in the gray matter during post-traumatic flexion. Finally, in extension, the injuries tested had little impact on the spinal cord. The capsular ligament was the most important structure to protect the spinal cord. Its status should be carefully examined during the patient's management.
屈曲-牵张损伤常导致创伤性颈脊髓损伤（SCI）。创伤后不稳定可在患者护理期间导致继发性脊髓损伤加重。然而，关于椎间盘韧带损伤模式如何影响脊髓损伤严重程度和机制的信息很少。本研究的目的是分析创伤后屈伸过程中后椎间盘韧带损伤如何影响脊髓压迫以及脊髓中的应力和应变模式。使用了一个包括脊髓的颈椎有限元模型，并在C4-C5、C5-C6或C6-C7模拟了部分或完全椎间盘（IVD）破裂与各种后韧带断裂的不同组合。在屈曲时，完全椎间盘破裂合并后韧带复合体破裂是最严重的损伤，导致脊髓中最高的冯·米塞斯应力（47-66kPa）、主应变p1（白质中为0.32-0.41）和p3（白质中为-0.78至-0.96）以及最高的脊髓压迫（35-48%）。创伤后脊髓损伤的主要机制被确定为损伤水平处前白质的压迫以及屈曲过程中脊髓后部的牵张。创伤后屈曲时灰质中也存在最大应力集中。最后，在伸展时，所测试的损伤对脊髓影响很小。关节囊韧带是保护脊髓的最重要结构。在患者管理过程中应仔细检查其状态。
