AuthorsMorteza Rasouligandomani 1, Alex del Arco 2, Francis Kiptengwer Chemorion 1,3,4, Marc-Antonio Bisotti 3, Fabio Galbusera 5, Jérôme Noailly 1, Miguel A. González Ballester 1,6Affiliations1. BCN MedTech, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain2. Hospital del Mar, Barcelona, Spain3. InSilicoTrials Technologies, Trieste, Italy4. Barcelona Supercomputing Center, Barcelona, Spain5. IRCCS Galeazzi, Milan, Italy; Schulthess Klinik, Zürich, Switzerland6. ICREA, Barcelona, SpainCorresponding authors: Morteza Rasouligandomani (morteza.rasouli@upf.edu), and Jérôme Noailly (jerome.noailly@upf.edu)AbstractAdult spine deformity (ASD) is prevalent and leads to a sagittal misalignment in the vertebral column. Computational methods, including Finite Element (FE) Models, have emerged as valuable tools for investigating the causes and treatment of ASD through biomechanical simulations. However, the process of generating personalized FE models is often complex and time-consuming. To address this challenge, we present a repository of FE models with diverse spine morphologies that statistically represent real geometries from a cohort of patients. These models are generated using EOS images, which are utilized to reconstruct 3D surface spine models. Subsequently, a Statistical Shape Model (SSM) is constructed, enabling the adaptation of a FE hexahedral mesh template for both the bone and soft tissues of the spine through mesh morphing. The SSM deformation fields facilitate the personalization of the mean hexahedral FE model based on sagittal balance measurements. Ultimately, this new hexahedral SSM tool offers a means to generate a virtual cohort of 16807 thoracolumbar FE spine models, which are openly shared in a public repository.
9 Figure 7: (a) Transferring triangulated mesh deformation vectors to hexahedral mesh correspondent points; (b) Automatized hexahedral SSM tool
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16807 thoracolumbar spine osteo-ligamentous hexahedral FE models, comprising point coordinates, were sampled from the automated hexahedral SSM tool (Figure 7b). This was accomplished by combining the first five principal components (PCs) and adjusting the shape modes using seven standard deviations (-3, -2, -1, 0, 1, 2, 3) for each mode. The sampled data, along with the corresponding spinopelvic measurements, is stored in a public repository. Notably, the hexahedral SSM tool (Figure 7b) is independent of image data and relies solely on sagittal parameters of the spine, such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL). Geometrical parameters can be measured using clinical software like sterEOS or Surgimap. By activating different shape modes, various spine deformities can be obtained. A comparison between the hexahedral SSM and geometrical data through a pros and cons analysis can facilitate the utilization of patient-personalized FE thoracolu
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Figure 8: Pipeline to generate FE patient-personalized thoracolumbar osteo-ligamentous spine model using hexahedral SSM tool and input geometrical parameters 42 patient-personalized thoracolumbar spine hexahedral models were reconstructed based on the spinopelvic parameters of the included patients (pipeline in Figure 8). These models have been archived in a publicly accessible repository. Figure 9 showcases the first 10 examples of these patient-personalized thoracolumbar spine hexahedral models. 10 Figure 9: First 10 patient-personalized thoracolumbar spine hexahedral models out of 42 cases
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Data Records The pipeline depicted in Figure 1 involves the sampling of 16807 triangulated and 16807 hexahedral thoracolumbar spine models utilizing the SSM and mesh morphing techniques. Furthermore, we provide 42 triangulated patient-personalized thoracolumbar spine EOS models obtained through sterEOS software, along with their corresponding 42 patientpersonalized hexahedral models generated via the SSM. The DICOM images were not shared due to an ethical approval for collected bi-planar EOS images from IRCCS Milan, mentioning that the images could be used for scientific reasons, but sharing the DICOM files of patients was not allowed. All the virtual cohort models and 42 patient-personalized hexahedral models can be generated using 42 shared triangulated patient-personalized thoracolumbar spine EOS models as shared in the current repository. The spinopelvic geometrical parameters were evaluated for each model. All the data, 694GB and consisting of 12.7 billion nodes, are shared in a
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