Van Toen C, Street J, Oxland T R, Cripton Peter A
Orthopaedic and Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC, V6T 1Z4, Canada.
Eur Spine J. 2015 Jan;24(1):136-47. doi: 10.1007/s00586-014-3612-4. Epub 2014 Oct 25.
Determine the effects of dynamic injurious axial compression applied at various lateral eccentricities (lateral distance to the centre of the spine) on mechanical flexibilities and structural injury patterns of the cervical spine.
13 three-vertebra human cadaver cervical spine specimens (6 C3-5, 3 C4-6, 2 C5-7, 2 C6-T1) were subjected to pure moment flexibility tests (±1.5 Nm) before and after impact trauma was applied in two groups: low and high lateral eccentricity (1 and 150 % of the lateral diameter of the vertebral body, respectively). Relative range of motion (ROM) and relative neutral zone (NZ) were calculated as the ratio of post and pre-trauma values. Injuries were diagnosed by a spine surgeon and scored. Classification functions were developed using discriminant analysis.
Low and high eccentric loading resulted in primarily bony fractures and soft tissue injuries, respectively. Axial impacts with high lateral eccentricities resulted in greater spinal motion in lateral bending [median relative ROM 3.5 (interquartile range, IQR 2.3) vs. 1.4 (IQR 0.5) and median relative NZ 4.7 (IQR 3.7) vs. 2.3 (IQR 1.1)] and in axial rotation [median relative ROM 5.3 (IQR 13.7) vs. 1.3 (IQR 0.5), p < 0.05 for all comparisons] than those that resulted from low eccentricity impacts. The developed classification functions had 92 % classification accuracy.
Dynamic axial compression loading of the cervical spine with high lateral eccentricities produced primarily soft tissue injuries resulting in more post-injury spinal flexibility in lateral bending and axial rotation than that associated with the bony fractures resulting from low eccentricity impacts.
确定在不同横向偏心距（到脊柱中心的横向距离）下施加动态损伤性轴向压缩对颈椎机械柔韧性和结构损伤模式的影响。
13个三节段人体尸体颈椎标本（6个C3 - 5、3个C4 - 6、2个C5 - 7、2个C6 - T1）在冲击创伤施加前后进行两组纯力矩柔韧性测试（±1.5 Nm）：低横向偏心距和高横向偏心距（分别为椎体横向直径的1%和150%）。相对运动范围（ROM）和相对中性区（NZ）计算为创伤后与创伤前值的比值。损伤由脊柱外科医生诊断并评分。使用判别分析开发分类函数。
低偏心加载和高偏心加载分别主要导致骨骨折和软组织损伤。高横向偏心距的轴向冲击导致侧弯时脊柱运动更大[相对ROM中位数3.5（四分位数间距，IQR 2.3）对1.4（IQR 0.5），相对NZ中位数4.7（IQR 3.7）对2.3（IQR 1.1）]以及轴向旋转时更大[相对ROM中位数5.3（IQR 13.7）对1.3（IQR 0.5），所有比较p < 0.05]，比低偏心距冲击导致的运动更大。所开发的分类函数具有92%的分类准确率。
高横向偏心距的颈椎动态轴向压缩加载主要产生软组织损伤，导致损伤后侧弯和轴向旋转的脊柱柔韧性比低偏心距冲击导致的骨骨折相关的柔韧性更大。
