前路融合术后持续性前屈载荷下邻近节段黏弹特性研究  

Viscoelastic properties of adjacent segments under prolonged flexion after anterior intervertebral fusion

作　　者：李慧[1] 王川[1] 刘振瑶 裴葆青[1] 杨晋才[2] 吴淑琴[1] 

机构地区：[1]北京航空航天大学生物与医学工程学院,北京100191 [2]北京朝阳医院骨科,北京100020

出　　处：《医用生物力学》2016年第1期50-55,共6页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(11372029)

摘　　要：目的分析前路融合术后持续性前屈载荷下邻近节段的黏弹力学特性,进一步了解椎间融合术后邻近节段加速退变的机制。方法采用羊腰椎双节段样本,分别对融合前后的样本施加相同前屈位姿载荷,持续时间30 min,记录力矩松弛和邻近节段角度数据。分别对两组力矩松弛数据进行拟合,得到定量的黏弹性比较结果。结果融合后整体的初始和最终力矩分别显著增大30.68%、34.34%。上邻近节段的黏弹性变形显著增大28.21%。Prony模型可以很好拟合力矩松弛曲线(R^2=99.50%),融合后的整体刚度显著增大47.82%和31.14%,黏性显著下降27.19%和28.76%(P<0.05)。结论融合术后脊柱保持相同姿态相同时间后,关节需承受更大的载荷以维持姿态;上邻近节段出现更大的黏弹性变形,增大不稳和损伤风险,均可能造成邻近节段加快退变。临床研究应更多关注准静态载荷对邻近节段退变发生的机制。Objective To analyze the viscoelastic properties of adjacent segments after anterior fusion under prolonged flexion,and further reveal the mechanism of accelerated adjacent segment degeneration after intervertebral fusion. Methods The same prolonged flexion lasted 30 minutes was applied on the two-level ovine lumbar specimen before and after anterior fusion respectively,and the moment relaxation and viscoelastic deformation of adjacent segments were measured. The moment relaxation curves from two groups were then fitted to obtain the quantitative viscoelastic results. Results After fusion,the initial and final moment in two groups significantly increased by 30. 68% and 34. 34%,and the viscoelastic deformation of the adjacent segments increased by28. 21%. The Prony model could perfectly fit the moment relaxation curves（ R^2= 99. 50%）. The integral stiffness significantly increased by 47. 82% and 31. 14% for two groups,while the viscoelasticity significantly decreased by27. 19% and 28. 16%,respectively（ P 〈0. 05）. Conclusions After intervertebral fusion,to maintain the same posture with the same time,the joints should bear larger loads than before. The viscoelastic deformation of adjacent segments becomes larger,which increases the risk of instability or injury,and further leads to the accelerated degeneration of adjacent segments. The mechanism of quasi-static daily loading on adjacent segment degeneration should be focused in clinical research.

关 键 词：脊柱 黏弹特性 力矩松弛 邻近节段退变 持续性前屈 椎间融合术 

分 类 号：R318.01[医药卫生—生物医学工程]