Load shift of the intervertebral disc after a vertebroplasty: a finite-element study
Load shift of the intervertebral disc after a vertebroplasty: a finite-element study
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DOI：
10.1007/s00586-002-0512-9
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发表时间：
2003-08-01
影响因子：
2.8
通讯作者：
Steffen, T
中科院分区：
文献类型：
--
作者：
Baroud, G;Nemes, J;Steffen, T
椎体成形术是一种新的稳定和预防骨质疏松性椎体骨折的手术方法。短期临床和生物力学结果令人鼓舞;然而，迄今为止，尚未发表长期结果的报告。我们的临床观察表明，椎体成形术可能会导致邻近椎体的骨折。在这一点上，只有有限的了解是什么原因导致这些骨折。我们之前假设相邻骨折可能是由于刚性增强后刚度和载荷的变化所致。本研究的目的是确定椎体成形术后腰椎运动节段的负荷转移。腰椎运动节段（L4-L5）的有限元（FE）模型用于量化和比较增强前后的刚度和增强椎骨附近椎间盘（IV）对准静态压缩的负载（负载转移）。结果表明，终板下的刚性骨水泥增强物作为一个直立的支柱，严重减少了增强椎骨终板的向内凸出。增强终板的隆起减少到增强前的7%，导致IV关节硬化约17%，整个运动节段硬化约11%。IV压力相应增加约19%，邻近增强端（L4下）的终板向内隆起显著增加约17%。邻近增强端的终板向内隆起增加了17%，这可能是邻近骨折的原因。
Infiltrating osteoporotic cancellous bone with bone cement (vertebroplasty) is a novel surgical procedure to stabilize and prevent osteoporotic vertebral fractures. Short-term clinical and biomechanical results are encouraging; however, so far no reports on long-term results have been published. Our clinical observations suggest that vertebroplasty may induce subsequent fractures in the vertebrae adjacent to the ones augmented. At this point, there is only a limited understanding of what causes these fractures. We have previously hypothesized that adjacent fractures may result from a shift in stiffness and load following rigid augmentation. The purpose of this study is to determine the load shift in a lumbar motion segment following vertebroplasty. A finite-element (FE) model of a lumbar motion segment (L4-L5) was used to quantify and compare the pre- and post-augmentation stiffness and loading (load shift) of the intervertebral (IV) disc adjacent to the augmented vertebra in response to quasi-static compression. The results showed that the rigid cement augmentation underneath the endplates acted as an upright pillar that severely reduced the inward bulge of the endplates of the augmented vertebra. The bulge of the augmented endplate was reduced to 7% of its value before the augmentation, resulting in a stiffening of the IV joint by approximately 17%, and of the whole motion segment by approximately 11%. The IV pressure accordingly increased by approximately 19%, and the inward bulge of the endplate adjacent to the one augmented (L4 inferior) increased considerably, by approximately 17%. This increase of up to 17% in the inward bulge of the endplate adjacent to the one augmented may be the cause of the adjacent fractures.