Dynamic biomechanical examination of the lumbar spine with implanted total spinal segment replacement (TSSR) utilizing a pendulum testing system.
Dynamic biomechanical examination of the lumbar spine with implanted total spinal segment replacement (TSSR) utilizing a pendulum testing system.
复制标题
DOI：
10.1371/journal.pone.0057412
复制
发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Crisco JJ
中科院分区：
文献类型：
--
作者：
Daniels AH;Paller DJ;Koruprolu S;Palumbo MA;Crisco JJ
脊柱运动保持植入物的生物力学研究有助于了解其在体内的行为。在这项研究中，我们假设在用钟摆系统进行模拟生理运动测试时，与天然功能脊柱单元相比，植入全脊柱节段置换术（TSSR）的腰椎会表现出更低的动态刚度和更快的能量吸收。在Flexuspine全脊柱节段置换术前后，用摆摆系统测试了5个未经处理的冷冻人体腰椎功能单元，轴向压缩载荷分别为181 N、282 N、385 N和488 N。通过将摆摆旋转5°开始测试屈曲、伸展和侧向弯曲；导致无约束振荡运动。记录达到平衡的旋转次数，计算并比较每种测试模式的弯曲刚度（N-m/°）。与完整的功能脊柱单元相比，在所有屈曲载荷下（p<0.011），在385 N和488 N的侧向弯曲载荷下（p<0.020），全脊柱节段置换达到平衡所需的周期明显减少。在完整的功能脊柱单元和全脊柱节段置换术中，屈伸和侧屈的平均弯曲刚度随着载荷的增加而增加（p<0.001），在任何测试模式下，完整的功能脊柱单元和全脊柱节段置换术之间的刚度没有显著差异（p< 0.18）。植入全脊柱节段置换术的腰椎功能脊柱单元具有相似的动态弯曲刚度，但在无约束摆系统的循环加载中，吸收能量的速度比完整的功能脊柱单元更快。尽管运动保持装置对临床性能的影响尚不完全清楚，但这些结果为该装置在近似生理负荷条件下的生物力学行为提供了进一步的见解。
Biomechanical investigations of spinal motion preserving implants help in the understanding of their in vivo behavior. In this study, we hypothesized that the lumbar spine with implanted total spinal segment replacement (TSSR) would exhibit decreased dynamic stiffness and more rapid energy absorption compared to native functional spinal units under simulated physiologic motion when tested with the pendulum system. Five unembalmed, frozen human lumbar functional spinal units were tested on the pendulum system with axial compressive loads of 181 N, 282 N, 385 N, and 488 N before and after Flexuspine total spinal segment replacement implantation. Testing in flexion, extension, and lateral bending began by rotating the pendulum to 5°; resulting in unconstrained oscillatory motion. The number of rotations to equilibrium was recorded and bending stiffness (N-m/°) was calculated and compared for each testing mode. The total spinal segment replacement reached equilibrium with significantly fewer cycles to equilibrium compared to the intact functional spinal unit at all loads in flexion (p<0.011), and at loads of 385 N and 488 N in lateral bending (p<0.020). Mean bending stiffness in flexion, extension, and lateral bending increased with increasing load for both the intact functional spinal unit and total spinal segment replacement constructs (p<0.001), with no significant differences in stiffness between the intact functional spinal unit and total spinal segment replacement in any of the test modes (p>0.18). Lumbar functional spinal units with implanted total spinal segment replacement were found to have similar dynamic bending stiffness, but absorbed energy at a more rapid rate than intact functional spinal units during cyclic loading with an unconstrained pendulum system. Although the effects on clinical performance of motion preserving devices is not fully known, these results provide further insight into the biomechanical behavior of this device under approximated physiologic loading conditions.
登录
查看更多内容
影响因子：
2.4
作者：
Gardner-Morse, MG;Stokes, IAF
通讯作者：
Stokes, IAF
影响因子：
3
作者：
Demetropoulos, Constantine K.;Sengupta, Dilip K.;Herkowitz, Harry N.
通讯作者：
Herkowitz, Harry N.
影响因子：
3
作者：
Grassmann, S;Oxland, TR;Nolte, LP
通讯作者：
Nolte, LP
影响因子：
3
作者：
Cunningham, BW;Gordon, JD;McAfee, PC
通讯作者：
McAfee, PC
影响因子：
3
作者：
NACHEMSON, A
通讯作者：
NACHEMSON, A