Lin Longwei, Zhang Xingze, Ma Xiang, Zhang Zepei, Miao Jun, Du Juan
Department of Spine Surgery, Tianjin Hospital, Tianjin, China.
Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.
BMC Musculoskelet Disord. 2025 Aug 11;26(1):773. doi: 10.1186/s12891-025-09038-4.
The aim of this study is to investigate the biomechanical changes in the sandwich vertebrae (SV), fractured vertebrae, and adjacent vertebrae at the thoracolumbar vertebrae in patients with osteoporotic vertebral compression fracture (OVCF) who underwent several percutaneous vertebroplasties (PVP) with varied cement volumes.
The finite element (FE) model of the T10-L2 thoracolumbar vertebral body is established. The augmented vertebrae (AV) of T11 and L1 is simulated and cylindrical bone cement is placed vertically in its center. The models are categorized into four types according to the volume of bone cement, 2mL bone cement group (model A), 4-mL bone cement group (model B), 6-mL bone cement group (model C), and 8-mL bone cement group (model D). By applying 500 N axial load on the upper surface of T10 and fixing the lower surface of L2, the maximum von Mises stress of the vertebrae and the maximum displacement of the sandwich vertebrae are analyzed and compared.
The maximum von Mises stresses of the T11 and L1 augmented vertebrae of Model C are lower than those of the fractured vertebrae of Models A and B in all directions of activity. The von Mises stresses of the augmented vertebrae of Model C and Model D are similar. The von Mises stresses of the fractured adjacent vertebrae T10 and L2, and the sandwich vertebrae T12 do not change significantly with the change in cement volume. In addition, the von Mises stress of T12 is lower than that of T10 in all four groups. The minimum value of T12 displacement in Model C is 3.0 mm.
Under the condition of no leakage, the stress distribution of the AV can be optimized by expanding the supporting area of bone cement to about 6 ml, which not only reduces the risk of recurrent fractures of adjacent vertebrae and AV, but also prolongs the service life of the implants by reducing the stress of bone cement, which provides the basis for the appropriate amount of bone cement required for clinical multi-level PVP.
本研究旨在调查接受多次经皮椎体成形术（PVP）且骨水泥用量不同的骨质疏松性椎体压缩骨折（OVCF）患者胸腰椎节段夹心椎体（SV）、骨折椎体及相邻椎体的生物力学变化。
建立T10 - L2胸腰椎椎体的有限元（FE）模型。模拟T11和L1的强化椎体（AV），并在其中心垂直放置圆柱形骨水泥。根据骨水泥体积将模型分为四种类型，即2mL骨水泥组（模型A）、4mL骨水泥组（模型B）、6mL骨水泥组（模型C）和8mL骨水泥组（模型D）。通过在T10上表面施加500N轴向载荷并固定L2下表面，分析并比较椎体的最大von Mises应力和夹心椎体的最大位移。
在所有活动方向上，模型C的T11和L1强化椎体的最大von Mises应力均低于模型A和B的骨折椎体。模型C和模型D的强化椎体的von Mises应力相似。骨折相邻椎体T10和L2以及夹心椎体T12的von Mises应力随骨水泥体积变化无显著改变。此外，在所有四组中，T12的von Mises应力均低于T10。模型C中T12位移的最小值为3.0mm。
在无渗漏的情况下，通过将骨水泥支撑面积扩大至约6ml可优化强化椎体的应力分布，这不仅降低了相邻椎体和强化椎体再次骨折的风险，还通过降低骨水泥应力延长了植入物的使用寿命，为临床多级PVP所需的合适骨水泥用量提供了依据。
