Experimental testing and biomechanical CT analysis of Chinese cadaveric vertebrae with different modeling approaches

• Published in: Medical engineering & physics Vol. 93; pp. 8 - 16
• Main Authors: Wei, Yi, Feng, Wentian, Li, Guanghui, Li, Zuchang, Liu, Zaiwei, Cheng, Xiaoguang, Yang, Haisheng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2021
• Subjects: aBMD, areal bone mineral density; Amin, vertebral minimum cross-sectional area; BCT, biomechanical computed tomography; Bone strength Abbreviations: OP, osteoporosis; CT-FEA, CT-based finite element analysis; D, vertebral body midline, anterior-posterior depth; DXA, dual-energy X-ray absorption; Finite element analysis; H, vertebral body height; HU, hounsfield unit; matBCT model, tetrahedral FE models created with a custom MATLAB program; Osteoporosis; PMMA, polymethylmethacrylate; QCT, quantitative computed tomography; Quantitative computed tomography; tetBCT model, tetrahedral FE models created in mimics; vBMD, volumetric bone mineral density; Vertebral fracture risk; voxBCT model, voxel-based hexahedral FE models; εhr, comp, high risk compressive strain; εhr, tens, high risk tensile strain; σhr, comp, high risk compressive stress; σhr, tens, high risk tensile stress; DXA, dual-energy X-ray absorption; voxBCT model, voxel-based hexahedral FE models; QCT, quantitative computed tomography; BCT, biomechanical computed tomography; HU, hounsfield unit; D, vertebral body midline, anterior-posterior depth; matBCT model, tetrahedral FE models created with a custom MATLAB program; εhr, comp, high risk compressive strain; Bone strength Abbreviations: OP, osteoporosis; CT-FEA, CT-based finite element analysis; tetBCT model, tetrahedral FE models created in mimics; Osteoporosis; PMMA, polymethylmethacrylate; Quantitative computed tomography; aBMD, areal bone mineral density; vBMD, volumetric bone mineral density; Vertebral fracture risk; Amin, vertebral minimum cross-sectional area; σhr, tens, high risk tensile stress; σhr, comp, high risk compressive stress; Finite element analysis; εhr, tens, high risk tensile strain; H, vertebral body height
• ISSN: 1350-4533; 1873-4030; 1873-4030
• DOI: 10.1016/j.medengphy.2021.05.008

Osteoporosis is characterized by reduced bone strength predisposing to an increased risk of fracture. Biomechanical computed tomography (BCT), predicting bone strength via CT-based finite element analysis (FEA), is now clinically available in the USA for diagnosing osteoporosis or assessing fracture risk. However, it has not been previously validated using a cohort of only Chinese subjects. Additionally, the effect of various modeling approaches on BCT outcomes remains elusive. To address these issues, we performed DXA and QCT scanning, compression testing, and BCT analyses on thirteen vertebrae derived from Chinese donors. Three BCT models were created (voxBCT and tetBCT: voxel-based and tetrahedral element-based FE models generated by a commercial software; matBCT: tetrahedral element-based FE model generated by a custom MATLAB program). BCT-computed outcomes were compared with experimental measures or between different BCT models. Results showed that, DXA-measured areal bone mineral density (aBMD) showed weak correlations with experimentally-measured vertebral stiffness (R2 = 0.28) and strength (R2 = 0.34). Compared to DXA-aBMD, BCT-computed stiffness provided improved correlations with experimentally-measured stiffness (voxBCT: R2 = 0.82; tetBCT: R2 = 0.77; matBCT: R2 = 0.76) and strength (voxBCT: R2 = 0.55; tetBCT: R2 = 0.57; matBCT: R2 = 0.53); BCT-computed mechanical parameters (stiffness, stress and strain) of the three different models were highly correlated with each other, with coefficient of determination (R2) values of 0.89–0.98. These results, based on a cohort of Chinese vertebral cadavers, suggest that BCT is superior over aBMD to consistently predict vertebral mechanical characteristics, regardless of the modeling approaches of choice. •Biomechanical computed tomography (BCT) was validated on a cohort of Chinese cadaveric vertebrae.•The effect of various modeling approaches (voxel vs tetrahedral element, commercial software vs custom program) was examined•BCT is superior over aBMD to predict vertebral mechanical characteristics, regardless of the modeling approaches of choice