Stemper Brian D, Yoganandan Narayan, Pintar Frank A, Shender Barry S, Paskoff Glenn R
Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Aviat Space Environ Med. 2009 May;80(5):489-94. doi: 10.3357/asem.2422.2009.
Vertebral fracture is the most common severe injury during high-speed pilot ejection. However, the loading paradigm experienced by pilots may also lead to soft-tissue spinal injuries that are more difficult to quantify and can lead to long-term deficits. This manuscript describes a new experimental protocol to simulate the effects of pilot ejection on the tissues of the head-neck complex. The model permits precise control of head-neck complex initial positioning, detailed analysis of head and spinal kinematics and upper and lower neck loads, and the ability to thoroughly investigate and identify soft-tissue injuries through upper and lower neck injury criteria, radiography, manual palpation, and cryomicrotomy. For the current test, peak acceleration of +14.8 Gz was similar to actual ejection events and duration of the acceleration pulse was approximately 100 ms. The specimen was oriented in flexion prior to initiation of inferior-to-superiorly directed acceleration. Subfailure ligamentum flavum injuries were sustained at the C4-C5 and C5-C6 cervical spinal levels and identified by increased segmental motions during the simulated ejection, increased laxity following testing, and cryomicrotomy. Upper and lower neck injury criteria did not predict these soft-tissue injuries. This experimental model can be used for detailed analysis of the effects of gender, head-neck orientation, helmet instrumentation, and acceleration pulse characteristics on cervical spine injury potential during pilot ejection events.
椎体骨折是高速飞行员弹射过程中最常见的严重损伤。然而，飞行员所经历的加载模式也可能导致软组织脊柱损伤，这种损伤更难量化，并且可能导致长期功能缺陷。本手稿描述了一种新的实验方案，以模拟飞行员弹射对头颈部复合体组织的影响。该模型允许对头颈部复合体的初始定位进行精确控制，对头和脊柱的运动学以及上下颈部负荷进行详细分析，并能够通过上下颈部损伤标准、放射成像、手动触诊和冷冻切片术彻底研究和识别软组织损伤。对于当前测试，+14.8 Gz的峰值加速度与实际弹射事件相似，加速度脉冲的持续时间约为100毫秒。在开始由下向上的加速度之前，标本处于屈曲位。在C4-C5和C5-C6颈椎水平发生了黄韧带亚失效损伤，通过模拟弹射过程中节段运动增加、测试后松弛度增加以及冷冻切片术得以识别。上下颈部损伤标准并未预测到这些软组织损伤。该实验模型可用于详细分析性别、头颈部方位、头盔仪器设备以及加速度脉冲特征对飞行员弹射事件期间颈椎损伤可能性的影响。
