Department of Mechanical Engineering, Tsinghua University, Beijing, China.
School of Mechanical Engineering and Automation, Northeastern University, Shenyang, 110819, China.
J Mater Sci Mater Med. 2022 Jun 3;33(6):52. doi: 10.1007/s10856-022-06671-6.
Under whole body vibration, how the cement augmentation affects the vibration characteristic of the osteoporotic fusion lumbar spine, complications, and fusion outcomes is unclear. A L1-L5 lumbar spine finite element model was developed to simulate a transforaminal lumbar interbody fusion (TLIF) model with bilateral pedicle screws at L4-L5 level, a polymethylmethacrylate (PMMA) cement-augmented TLIF model (TLIF-PMMA) and an osteoporotic TLIF model. A 40 N sinusoidal vertical load at 5 Hz and a 400 N preload were utilized to simulate a vertical vibration of the human body and the physiological compression caused by muscle contraction and the weight of human body. The results showed that PMMA cement augmentation may produce a stiffer pedicle screw/rod construct and decrease the risk of adjacent segment disease, subsidence, and rod failure under whole-body vibration(WBV). Cement augmentation might restore the disc height and segmental lordosis and decrease the risk of poor outcomes, but it might also increase the risk of cage failure and prolong the period of lumbar fusion under WBV. The findings may provide new insights for performing lumbar interbody fusion in patients affected by osteoporosis of the lumbar spine. Graphical abstract.
在全身振动下，骨水泥增强如何影响骨质疏松性融合腰椎的振动特性、并发症和融合效果尚不清楚。本研究建立了一个 L1-L5 腰椎有限元模型，模拟经椎间孔腰椎体间融合术（TLIF）模型，在 L4-L5 水平双侧椎弓根螺钉、聚甲基丙烯酸甲酯（PMMA）水泥增强 TLIF 模型（TLIF-PMMA）和骨质疏松 TLIF 模型。采用 5Hz 的 40N 正弦垂直载荷和 400N 预载模拟人体垂直振动以及肌肉收缩和人体重量引起的生理压缩。结果表明，PMMA 骨水泥增强可能会产生更硬的椎弓根螺钉/棒结构，并降低全身振动（WBV）下邻近节段疾病、沉降和棒断裂的风险。骨水泥增强可能会恢复椎间盘高度和节段前凸，并降低不良结果的风险，但也可能会增加 cage 失败的风险，并延长 WBV 下腰椎融合的时间。这些发现可能为骨质疏松性腰椎病变患者进行腰椎体间融合提供新的见解。图摘要。
