Liang De, Ye Lin-Qiang, Jiang Xiao-Bing, Yang Pan, Zhou Guang-Quan, Yao Zhen-Song, Zhang Shun-Cong, Yang Zhi-Dong
Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.
Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China; Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People's Republic of China.
J Surg Res. 2015 May 1;195(1):246-56. doi: 10.1016/j.jss.2014.12.053. Epub 2015 Jan 7.
According to some clinical studies, insufficient cement distribution (ID) in the fractured area and asymmetrical cement distribution around the fractured area were thought to be the reasons for unrelieved pain and recollapse after percutaneous vertebral augmentation (PVA) in the treatment of symptomatic osteoporotic vertebral compression fractures.
Finite element methods were used to investigate the biomechanical variance among three patterns of cement distribution (ID and sufficient cement distribution in the fractured area and asymmetrical cement distribution around the fractured area including upward [BU] and downward [BD] cement distribution).
Compared with fractured vertebra before PVA, distribution of von Mises stress in the cancellous bone was transferred to be concentrated at the cancellous bone surrounding cement after PVA, whereas it was not changed in the cortical bone. Compared with sufficient cement distribution group, maximum von Mises stress in the cancellous bone and cortical bone and maximum displacement of augmented vertebra increased significantly in the ID group, whereas asymmetrical cement distribution around the fractured area in BU and BD groups mainly increased maximum von Mises stress in the cancellous bone significantly. Similar results could be seen in all loading conditions.
ID in the fractured area may lead to unrelieved pain after PVA in the treatment of symptomatic osteoporotic vertebral compression fractures as maximum displacement of augmented vertebral body increased significantly. Both ID in the fractured area and asymmetrical cement distribution around the fractured area are more likely to induce recollapse of augmented vertebra because they increased maximum von Mises stress in the cancellous bone and cortical bone of augmented vertebra significantly.
根据一些临床研究，骨折区域骨水泥分布不足（ID）以及骨折区域周围骨水泥分布不对称被认为是经皮椎体强化术（PVA）治疗症状性骨质疏松性椎体压缩骨折后疼痛未缓解和再次塌陷的原因。
采用有限元方法研究三种骨水泥分布模式（ID、骨折区域骨水泥分布充足以及骨折区域周围骨水泥分布不对称，包括向上[BU]和向下[BD]骨水泥分布）之间的生物力学差异。
与PVA术前的骨折椎体相比，PVA术后松质骨中的von Mises应力分布转移并集中在骨水泥周围的松质骨，而皮质骨中的应力分布未发生变化。与骨水泥分布充足组相比，ID组松质骨和皮质骨中的最大von Mises应力以及强化椎体的最大位移显著增加，而BU组和BD组骨折区域周围骨水泥分布不对称主要显著增加了松质骨中的最大von Mises应力。在所有加载条件下均可见类似结果。
骨折区域的ID可能导致PVA治疗症状性骨质疏松性椎体压缩骨折后疼痛未缓解，因为强化椎体的最大位移显著增加。骨折区域的ID以及骨折区域周围骨水泥分布不对称更有可能导致强化椎体再次塌陷，因为它们显著增加了强化椎体松质骨和皮质骨中的最大von Mises应力。
