Ivancic Paul C, Ito Shigeki, Panjabi Manohar M, Pearson Adam M, Tominaga Yasuhiro, Wang Jaw-Lin, Gimenez S Elena
Biomechanics Research Laboratory, Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, Connecticut, USA.
Traffic Inj Prev. 2005 Jun;6(2):175-84. doi: 10.1080/15389580590931671.
The Intervertebral Neck Injury Criterion (IV-NIC) is based on the hypothesis that dynamic intervertebral motion beyond physiological limits may injure soft tissues. In contrast, the Neck Injury Criterion (NIC) hypothesizes that sudden change in spinal fluid pressure may cause neural injuries. The goals of this study, using the biofidelic whole human cervical spine model with muscle force replication, were to determine the IV-NIC injury threshold due to frontal impact at each intervertebral level, and to compare the IV-NIC and NIC in determining injury.
Using a bench-top apparatus, frontal impacts were simulated at 4, 6, 8, and 10 g horizontal accelerations of the T1 vertebra. Pre- and post-trauma flexibility testing measured the soft tissue injury; that is, a significant increase (p < 0.05) in neutral zone or range of motion at any intervertebral level, above the corresponding physiological limit.
Results indicated that the soft tissue injury occurred due to flexion mode of injury and its threshold was 8 g. The average IV-NIC injury threshold (95% confidence interval) was 2.0 (1.2-2.8) at C4-C5 and 2.3 (1.6-3.0) at C6-C7, while the average NIC injury threshold was 18.4 (17.9-19.0) m(2)/s(2). The NIC injury threshold was reached significantly earlier than all the IV-NIC injury thresholds, demonstrating that the NIC may be unable to predict facet and soft tissue injury caused by non-physiologic inververtebral rotation.
Present results suggest that IV-NIC is an effective tool for determining soft tissue neck injuries by identifying the intervertebral level, mode, time, and severity of injury.
颈椎间盘损伤标准（IV-NIC）基于这样一种假设，即超出生理极限的动态椎间盘运动可能会损伤软组织。相比之下，颈部损伤标准（NIC）假设脑脊液压力的突然变化可能导致神经损伤。本研究的目的是使用具有肌肉力复制功能的生物逼真全人颈椎模型，确定每个椎间盘水平因正面撞击导致的IV-NIC损伤阈值，并比较IV-NIC和NIC在确定损伤方面的情况。
使用台式装置，在T1椎体水平以4、6、8和10g的水平加速度模拟正面撞击。创伤前后的柔韧性测试测量软组织损伤情况，即在任何椎间盘水平，中性区或运动范围在相应生理极限之上出现显著增加（p<0.05）。
结果表明，软组织损伤是由屈曲损伤模式引起的，其阈值为8g。C4-C5水平的平均IV-NIC损伤阈值（95%置信区间）为2.0（1.2-2.8），C6-C7水平为2.3（1.6-3.0），而平均NIC损伤阈值为18.4（17.9-19.0）m²/s²。NIC损伤阈值比所有IV-NIC损伤阈值更早达到显著水平，这表明NIC可能无法预测由非生理性椎间盘旋转引起的小关节和软组织损伤。
目前的结果表明，IV-NIC是一种有效的工具，可通过确定损伤的椎间盘水平、模式、时间和严重程度来确定颈部软组织损伤。
