骨质疏松症成像：骨保存对基于MDCT的小梁骨微观结构参数和有限元模型的影响。

Osteoporosis imaging: effects of bone preservation on MDCT-based trabecular bone microstructure parameters and finite element models.

作者信息

Baum Thomas, Grande Garcia Eduardo, Burgkart Rainer, Gordijenko Olga, Liebl Hans, Jungmann Pia M, Gruber Michael, Zahel Tina, Rummeny Ernst J, Waldt Simone, Bauer Jan S

机构信息

Institut für Radiologie, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, München, Germany.

Klinik für Orthopädie, Abteilung für Biomechanik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, München, Germany.

出版信息

BMC Med Imaging. 2015 Jun 26;15:22. doi: 10.1186/s12880-015-0066-z.

DOI:10.1186/s12880-015-0066-z

PMID:26113362

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4482285/

Abstract

BACKGROUND

Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength due to a reduction of bone mass and deterioration of bone microstructure predisposing an individual to an increased risk of fracture. Trabecular bone microstructure analysis and finite element models (FEM) have shown to improve the prediction of bone strength beyond bone mineral density (BMD) measurements. These computational methods have been developed and validated in specimens preserved in formalin solution or by freezing. However, little is known about the effects of preservation on trabecular bone microstructure and FEM. The purpose of this observational study was to investigate the effects of preservation on trabecular bone microstructure and FEM in human vertebrae.

METHODS

Four thoracic vertebrae were harvested from each of three fresh human cadavers (n=12). Multi-detector computed tomography (MDCT) images were obtained at baseline, 3 and 6 month follow-up. In the intervals between MDCT imaging, two vertebrae from each donor were formalin-fixed and frozen, respectively. BMD, trabecular bone microstructure parameters (histomorphometry and fractal dimension), and FEM-based apparent compressive modulus (ACM) were determined in the MDCT images and validated by mechanical testing to failure of the vertebrae after 6 months.

RESULTS

Changes of BMD, trabecular bone microstructure parameters, and FEM-based ACM in formalin-fixed and frozen vertebrae over 6 months ranged between 1.0-5.6% and 1.3-6.1%, respectively, and were not statistically significant (p>0.05). BMD, trabecular bone microstructure parameters, and FEM-based ACM as assessed at baseline, 3 and 6 month follow-up correlated significantly with mechanically determined failure load (r=0.89-0.99; p<0.05). The correlation coefficients r were not significantly different for the two preservation methods (p>0.05).

CONCLUSIONS

Formalin fixation and freezing up to six months showed no significant effects on trabecular bone microstructure and FEM-based ACM in human vertebrae and may both be used in corresponding in-vitro experiments in the context of osteoporosis.

摘要

背景

骨质疏松症被定义为一种骨骼疾病，其特征是由于骨量减少和骨微结构退化导致骨强度受损，使个体骨折风险增加。小梁骨微结构分析和有限元模型（FEM）已显示出能在骨矿物质密度（BMD）测量之外改善对骨强度的预测。这些计算方法已在福尔马林溶液中保存或冷冻保存的标本中得到开发和验证。然而，关于保存对小梁骨微结构和有限元模型的影响知之甚少。本观察性研究的目的是调查保存对人椎骨小梁骨微结构和有限元模型的影响。

方法

从三具新鲜人体尸体中各采集四个胸椎（n = 12）。在基线、3个月和6个月随访时获取多排螺旋计算机断层扫描（MDCT）图像。在MDCT成像间隔期间，每个供体的两个椎骨分别用福尔马林固定和冷冻。在MDCT图像中确定BMD、小梁骨微结构参数（组织形态计量学和分形维数）以及基于有限元模型的表观压缩模量（ACM），并在6个月后通过对椎骨进行力学测试直至破坏来验证。

结果

福尔马林固定和冷冻的椎骨在6个月内BMD、小梁骨微结构参数以及基于有限元模型的ACM变化分别在1.0 - 5.6%和1.3 - 6.1%之间，且无统计学意义（p > 0.05）。在基线、3个月和6个月随访时评估的BMD、小梁骨微结构参数以及基于有限元模型的ACM与力学测定的破坏载荷显著相关（r = 0.89 - 0.99；p < 0.05）。两种保存方法的相关系数r无显著差异（p > 0.05）。