Bassani Tito, Ottardi Claudia, Costa Francesco, Brayda-Bruno Marco, Wilke Hans-Joachim, Galbusera Fabio
IRCCS Istituto Ortopedico Galeazzi , Milan , Italy.
Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering 'Giulio Natta', Politecnico di Milano , Milan , Italy.
Front Bioeng Biotechnol. 2017 Jan 20;5:1. doi: 10.3389/fbioe.2017.00001. eCollection 2017.
The present study proposes a semiautomatic software approach to reconstruct 3D subject-specific musculoskeletal model of thoracolumbar spine from radiographic digitized images acquired with EOS system. The approach is applied to evaluate the intervertebral loads in 38 standing adolescents with mild idiopathic scoliosis. For each vertebra, a set of landmarks was manually identified on radiographic images. The landmark coordinates were processed to calculate the following vertebral geometrical properties in the 3D space (i) location (ii) dimensions; and (iii) rotations. Spherical joints simulated disks, ligaments, and facet joints. Body weight distribution, muscles forces, and insertion points were placed according to physiological-anatomical values. Inverse static analysis, calculating joints' reactions in maintaining assigned spine configuration, was performed with AnyBody software. Reaction forces were computed to quantify intervertebral loads, and correlation with the patient anatomical parameters was then checked. Preliminary validation was performed comparing the model outcomes with that obtained from other authors in previous modeling works and from measurements. The comparison with previous modeling works and studies partially fulfilled the preliminary validation purpose. However, minor incongruities were pointed out that need further investigations. The subjects' intervertebral loads were found significantly correlated with the anatomical parameters in the sagittal and axial planes. Despite preliminary encouraging results that support model suitability, future investigations to consolidate the proposed approach are necessary. Nonetheless, the present method appears to be a promising tool that once fully validated could allow the subject-specific non-invasive evaluation of a deformed spine, providing supplementary information to the routine clinical examination and surgical intervention planning.
本研究提出了一种半自动软件方法，用于从EOS系统获取的数字化X线影像重建胸腰椎的三维个体特异性肌肉骨骼模型。该方法应用于评估38名患有轻度特发性脊柱侧凸的站立青少年的椎间负荷。对于每个椎体，在X线影像上手动识别一组标志点。对标志点坐标进行处理，以计算三维空间中以下椎体几何特性：(i)位置；(ii)尺寸；以及(iii)旋转。球形关节模拟椎间盘、韧带和小关节。根据生理解剖学值放置体重分布、肌肉力量和附着点。使用AnyBody软件进行逆静态分析，计算维持指定脊柱构型时关节的反应力。计算反应力以量化椎间负荷，然后检查其与患者解剖参数的相关性。通过将模型结果与其他作者在先前建模工作中获得的结果以及测量结果进行比较，进行了初步验证。与先前建模工作和研究的比较部分实现了初步验证目的。然而，指出了一些小的不一致之处，需要进一步研究。发现受试者的椎间负荷与矢状面和轴平面的解剖参数显著相关。尽管初步令人鼓舞的结果支持模型的适用性，但仍有必要进行进一步研究以巩固所提出的方法。尽管如此，本方法似乎是一种有前途的工具，一旦得到充分验证，可允许对变形脊柱进行个体特异性非侵入性评估，为常规临床检查和手术干预规划提供补充信息。
