Department of Neurosurgery, Eulji University Eulji Hospital, Nowon-gu, Republic of Korea.
Department of Neurosurgery, Hanyang University Medical Center, Seongdong-gu, Seoul, Republic of Korea.
PLoS One. 2020 Dec 11;15(12):e0243771. doi: 10.1371/journal.pone.0243771. eCollection 2020.
This study aimed to investigate the biomechanical effects of a newly developed interspinous process device (IPD), called TAU. This device was compared with another IPD (SPIRE) and the pedicle screw fixation (PSF) technique at the surgical and adjacent levels of the lumbar spine.
A three-dimensional finite element model analysis of the L1-S1 segments was performed to assess the biomechanical effects of the proposed IPD combined with an interbody cage. Three surgical models-two IPD models (TAU and SPIRE) and one PSF model-were developed. The biomechanical effects, such as range of motion (ROM), intradiscal pressure (IDP), disc stress, and facet loads during extension were analyzed at surgical (L3-L4) and adjacent levels (L2-L3 and L4-L5). The study analyzed biomechanical parameters assuming that the implants were perfectly fused with the lumbar spine.
The TAU model resulted in a 45%, 49%, 65%, and 51% decrease in the ROM at the surgical level in flexion, extension, lateral bending, and axial rotation, respectively, when compared to the intact model. Compared to the SPIRE model, TAU demonstrated advantages in stabilizing the surgical level, in all directions. In addition, the TAU model increased IDP at the L2-L3 and L4-L5 levels by 118.0% and 78.5% in flexion, 92.6% and 65.5% in extension, 84.4% and 82.3% in lateral bending, and 125.8% and 218.8% in axial rotation, respectively. Further, the TAU model exhibited less compensation at adjacent levels than the PSF model in terms of ROM, IDP, disc stress, and facet loads, which may lower the incidence of the adjacent segment disease (ASD).
The TAU model demonstrated more stabilization at the surgical level than SPIRE but less stabilization than the PSF model. Further, the TAU model demonstrated less compensation at adjacent levels than the PSF model, which may lower the incidence of ASD in the long term. The TAU device can be used as an alternative system for treating degenerative lumbar disease while maintaining the physiological properties of the lumbar spine and minimizing the degeneration of adjacent segments.
本研究旨在探讨一种新型棘突间装置（IPD）TAU 的生物力学效应。该装置与另一种 IPD（SPIRE）和椎弓根螺钉固定（PSF）技术在腰椎的手术节段和相邻节段进行了比较。
对 L1-S1 节段进行了三维有限元模型分析，以评估所提出的 IPD 与椎间笼结合的生物力学效应。建立了三种手术模型——两种 IPD 模型（TAU 和 SPIRE）和一种 PSF 模型。在伸展时，分析了手术（L3-L4）和相邻节段（L2-L3 和 L4-L5）的运动范围（ROM）、椎间盘内压力（IDP）、椎间盘应力和小关节负荷等生物力学效应。研究假设植入物与腰椎完全融合，分析了生物力学参数。
与完整模型相比，TAU 模型在手术节段的屈伸、侧屈和轴向旋转方向的 ROM 分别减少了 45%、49%、65%和 51%。与 SPIRE 模型相比，TAU 在所有方向上都具有稳定手术节段的优势。此外，TAU 模型在屈曲时使 L2-L3 和 L4-L5 节段的 IDP 增加了 118.0%和 78.5%，在伸展时增加了 92.6%和 65.5%，在侧屈时增加了 84.4%和 82.3%，在轴向旋转时增加了 125.8%和 218.8%。此外，与 PSF 模型相比，TAU 模型在 ROM、IDP、椎间盘应力和小关节负荷方面在相邻节段的代偿作用较小，这可能会降低相邻节段疾病（ASD）的发生率。
与 SPIRE 相比，TAU 模型在手术节段的稳定性更好，但不如 PSF 模型。此外，与 PSF 模型相比，TAU 模型在相邻节段的代偿作用较小，这可能会降低 ASD 的长期发生率。TAU 装置可作为治疗退行性腰椎疾病的替代系统，同时保持腰椎的生理特性，并最大限度地减少相邻节段的退变。
