Sun Peidong, Zhao Weidong, Bi Zhenyu, Wu Changfu, Ouyang Jun
Department of Anatomy, Guangdong Provincial Medical Biomechanical Key Laboratory, Southern Medical University, Guangzhou, China.
Acta Bioeng Biomech. 2012;14(1):45-9.
An understanding of the load transfer within spinal posterior column of lumbar spine is necessary to determine the influence of mechanical factors on potential mechanisms of the motion-sparing implant such as artificial intervertebral disc and the dynamic spine stabilization systems. In this study, a new method has been developed for evaluating the load bearing of spinal posterior column by the surface strain of spinal pedicle response to the loading of spinal segment. Six cadaveric lumbar spine segments were biomechanically evaluated between levels L1 and L5 in intact condition and the strain gauges were pasted to an inferior surface of L2 pedicles. Multidirectional flexibility testing used the Panjabi testing protocol; pure moments for the intact condition with overall spinal motion and unconstrained intact moments of ±8 Nm were used for flexion-extension and lateral bending testing. High correlation coefficient (0.967-0.998) indicated a good agreement between the load of spinal segment and the surface strain of pedicle in all loading directions. Principal compressive strain could be observed in flexion direction and tensile strain in extension direction, respectively. In conclusion, the new method seems to be effective for evaluating posterior spinal column loads using pedicles' surface strain data collected during biomechanical testing of spine segments.
了解腰椎脊柱后柱内的负荷传递对于确定机械因素对诸如人工椎间盘和动态脊柱稳定系统等保留运动功能植入物潜在机制的影响是必要的。在本研究中，已开发出一种新方法，通过脊柱椎弓根对脊柱节段负荷的表面应变来评估脊柱后柱的负荷承载能力。对六个尸体腰椎节段在L1和L5节段之间的完整状态进行了生物力学评估，并将应变片粘贴到L2椎弓根的下表面。多方向灵活性测试采用潘贾比测试方案；完整状态下的纯力矩用于整体脊柱运动，±8 Nm的无约束完整力矩用于屈伸和侧弯测试。高相关系数（0.967 - 0.998）表明在所有加载方向上脊柱节段的负荷与椎弓根的表面应变之间具有良好的一致性。分别在屈曲方向可观察到主压缩应变，在伸展方向可观察到拉伸应变。总之，新方法似乎对于使用脊柱节段生物力学测试期间收集的椎弓根表面应变数据来评估脊柱后柱负荷是有效的。
