Costa M C, Campello L B Bresani, Ryan M, Rochester J, Viceconti M, Dall'Ara E
Department of Oncology and Metabolism, Mellanby Centre for bone Research, University of Sheffield, UK.
INSIGNEO Institute for in silico Medicine, University of Sheffield, UK.
Bone Rep. 2020 Mar 9;12:100257. doi: 10.1016/j.bonr.2020.100257. eCollection 2020 Jun.
Currently, the Spinal Instability Neoplastic Score system is used in clinics to evaluate the risk of fracture in patients with spinal metastases. This method, however, does not always provide a clear guideline due to the complexity in accounting for the effect of metastatic lesions on vertebral stability. The aim of this study was to use a validated micro Finite Element (microFE) modelling approach to analyse the effect of the size and location of lytic metastases on the mechanical properties of human vertebral bodies. Micro Computed Tomography based microFE models were generated with and without lytic lesions simulated as holes within a human vertebral body. Single and multiple lytic lesions were simulated with four different sizes and in five different locations. Bone was assumed homogenous, isotropic and linear elastic, and each vertebra was loaded in axial compression. It was observed that the size of lytic lesions was linearly related with the reduction in structural properties of the vertebral body (reduction of stiffness between 3% and 30% for lesion volume between 4% and 35%). The location of lytic lesions did not show a clear effect on predicted structural properties. Single or multiple lesions with the same volume provided similar results. Locally, there was a homogeneous distribution of axial principal strains among the models with and without lytic lesions. This study highlights the potential of microFE models to study the effect of lesions on the mechanical properties of the human vertebral body.
目前，脊柱不稳定肿瘤评分系统在临床上用于评估脊柱转移瘤患者的骨折风险。然而，由于在考虑转移瘤对椎体稳定性的影响方面存在复杂性，这种方法并不总是能提供明确的指导方针。本研究的目的是使用经过验证的微观有限元（microFE）建模方法，分析溶骨性转移瘤的大小和位置对人体椎体力学性能的影响。基于微型计算机断层扫描生成了包含和不包含模拟为人体椎体内孔洞的溶骨性病变的microFE模型。模拟了单个和多个溶骨性病变，其大小有四种，位置有五种。假定骨骼是均匀、各向同性和线弹性的，并且每个椎体承受轴向压缩载荷。观察到溶骨性病变的大小与椎体结构性能的降低呈线性相关（对于4%至35%的病变体积，刚度降低3%至30%）。溶骨性病变的位置对预测的结构性能没有明显影响。相同体积的单个或多个病变提供了相似的结果。在局部，有溶骨性病变和无溶骨性病变的模型中轴向主应变分布均匀。本研究强调了microFE模型在研究病变对人体椎体力学性能影响方面的潜力。
