Beaubien Brian P, Freeman Andrew L, Buttermann Glenn R
Excelen Center for Bone and Joint Research and Education, 700 10th Avenue South, Minneapolis, MN55415, United States.
Excelen Center for Bone and Joint Research and Education, 700 10th Avenue South, Minneapolis, MN55415, United States.
J Biomech. 2016 Jan 25;49(2):216-21. doi: 10.1016/j.jbiomech.2015.12.012. Epub 2015 Dec 11.
The spinous processes and supraspinous and interspinous ligaments (SSL and ISL, respectively) limit flexion and may relate to spinal curvature. Spinous process angles and mechanical properties of explanted human thoracic posterior SSL/ISL complexes were compared for scoliosis (n=14) vs. kyphosis (n=8) patients. The median thoracic coronal Cobb angle for scoliosis patients was 48°, and sagittal angles for kyphosis patients was 78°. Spinous processes were gripped and four strain steps of 4% were applied and held. Percent relaxation was calculated over each step, equilibrium load data were fit to an exponential equation, and a Kelvin model was fit to the load from all four curves. Failure testing was also performed. Median ligament complex dimensions from scoliosis and kyphosis patients were, respectively: ISL width=16.5mm and 16.0mm; SSL width=4.3mm and 3.8mm; ISL+SSL area=17.2mm and 25.7mm; these differences were not significant. Significant differences did exist in terms of spinous process angle vs. spine axis (47° for scoliosis and 32° for kyphosis) and SSL thickness (2.1mm for scoliosis and 3.0mm for kyphosis). Fourth-step median relaxation was 42% for scoliosis and 49% for kyphosis. Median linear region stiffness was 42N/mm for scoliosis and 51N/mm for kyphosis. Median failure load was 191N for scoliotic and 175N for kyphotic ligaments. Differences in loading, relaxation, viscoelastic and failure parameters were not statistically significant, except for a trend for greater initial rate of relaxation (T1) for scoliosis ligaments. However, we found significant morphological differences related to the spinous processes, which suggests a need for future biomechanical studies related to the musculoskeletal aspects of spinal alignment and posture.
棘突以及棘上韧带和棘间韧带（分别为SSL和ISL）限制脊柱前屈，可能与脊柱曲度有关。比较了脊柱侧凸患者（n = 14）和脊柱后凸患者（n = 8）的棘突角度以及取出的人胸段后部SSL/ISL复合体的力学性能。脊柱侧凸患者胸段冠状面Cobb角中位数为48°，脊柱后凸患者矢状面角度为78°。抓住棘突并施加4%的四个应变步骤并保持。计算每个步骤的松弛百分比，将平衡负荷数据拟合到指数方程，并将开尔文模型拟合到所有四条曲线的负荷。还进行了失效测试。脊柱侧凸和脊柱后凸患者韧带复合体尺寸中位数分别为：ISL宽度 = 16.5mm和16.0mm；SSL宽度 = 4.3mm和3.8mm；ISL + SSL面积 = 17.2mm和25.7mm；这些差异不显著。棘突角度与脊柱轴线（脊柱侧凸为47°，脊柱后凸为32°）和SSL厚度（脊柱侧凸为2.1mm，脊柱后凸为3.0mm）方面确实存在显著差异。第四步脊柱侧凸的中位数松弛率为42%，脊柱后凸为49%。脊柱侧凸的中位数线性区域刚度为42N/mm，脊柱后凸为51N/mm。脊柱侧凸韧带的中位数失效负荷为191N，脊柱后凸韧带为175N。除了脊柱侧凸韧带的初始松弛率（T1）有更大的趋势外，负荷、松弛、粘弹性和失效参数的差异无统计学意义。然而，我们发现与棘突相关的显著形态学差异，这表明未来需要进行与脊柱排列和姿势的肌肉骨骼方面相关的生物力学研究。
