This study aimed to compare the effects of whole-body vibration on the biomechanics of a fused lumbar spine with different posterior stabilisers, including an interspinous process spacer (IPS) and a bilateral pedicle screw system (BPSS). A finite-element model of lumbar interbody fusion with an IPS or a BPSS at the L4–L5 level was constructed based on a healthy human whole lumbar spine. Transient dynamic and static analyses were employed to compute the dynamic responses of deformation and stress for the models to a sinusoidal axial vibration load of ±40 N and its corresponding static axial loads (−40 and 40 N), respectively. The results showed that for both the IPS and BPSS models, the vibration amplitudes of the responses were significantly higher than the corresponding changing amplitudes under static loads. The increasing effect of vibration load on endplate stress at L4–L5 reached 128.3 and 146.0% for the IPS and BPSS models, respectively. In contrast, the increasing effects of vibration load on disc bulge and annulus stress at adjacent L3–L4 were nearly the same for these two models. This indicates that the vibration sensitivity of a fused level is lower when using an IPS compared with that when using a BPSS, but there is no obvious difference in the vibration sensitivity of the adjacent level when using these two stabilisers.

中文翻译：

---

振动对不同稳定器融合腰椎的生物力学影响

本研究旨在比较全身振动对具有不同后稳定器（包括​​棘突间间隔器 (IPS) 和双侧椎弓根螺钉系统 (BPSS)）的融合腰椎的生物力学的影响。基于健康人的整个腰椎构建了 L4-L5 水平 IPS 或 BPSS 腰椎椎间融合的有限元模型。采用瞬态动态和静态分析来分别计算模型对±40 N 的正弦轴向振动载荷及其相应的静态轴向载荷（-40 和 40 N）的变形和应力的动态响应。结果表明，对于 IPS 和 BPSS 模型，响应的振动幅度明显高于静态负载下相应的变化幅度。对于 IPS 和 BPSS 模型，振动载荷对 L4–L5 端板应力的增加效应分别达到 128.3% 和 146.0%。相反，对于这两个模型，振动载荷对相邻 L3-L4 椎间盘突出和环应力的增加影响几乎相同。这表明使用 IPS 时与使用 BPSS 时相比，融合级的振动灵敏度较低，但使用这两种稳定器时相邻级的振动灵敏度没有明显差异。