Semiautomated 3D Spine Reconstruction from Biplanar Radiographic Images: Prediction of Intervertebral Loading in Scoliotic Subjects

Abstract

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 in vivo measurements. The comparison with previous modeling works and in vivo 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.

Spinal Compressive Forces in Adolescent Idiopathic Scoliosis With and Without Carrying Loads: A Musculoskeletal Modeling Study

“…Using our enhanced base models, we created subject-specific models for 24 patients with mild to moderate AIS ( Table 1). Spinal deformity was thereby implemented based on existing simultaneously captured and spatially calibrated anteriorposterior and lateral radiographic images (EOS Imaging, France) that were acquired within a previous study conducted at the IRCCS Istituto Ortopedico Galeazzi in Milan, Italy (Bassani et al, 2017). The protocol for this study was approved by the local ethics commission and patient assent and parental permission to use the anonymized radiological data were given by signing a written informed consent form.…”

Collagen Hybrid Formulations for the 3D Printing of Nanostructured Bone Scaffolds: An Optimized Genipin-Crosslinking Strategy

“…The final design of the nanostructured constructs highly depends on a proper combination of materials and manufacturing technology. Conventional techniques are normally based on subtractive methods that limit the precise control over the final morphological features, at variance with 3D printing that has emerged as the most suitable and versatile technology for the fabrication of complex scaffold microarchitectures [ 28 , 29 , 30 , 31 ]. Extrusion-based 3D-printing technologies have thus significantly increased the scaffold manufacturing precision, as well as process repeatability and biocompatibility [ 5 , 30 , 31 ].…”

Adult Stem Cells Spheroids to Optimize Cell Colonization in Scaffolds for Cartilage and Bone Tissue Engineering

“…Biofabrication can be defined as “the automated generation of biologically functional products with structural organization from living cells, bioactive molecules, biomaterials, cell aggregates such as micro-tissues, or hybrid cell-material constructs, through bioprinting or bioassembly and subsequent tissue maturation processes” [ 84 ]. Biofabrication methods have already been applied with cells and scaffolds to bone tissue engineering and connective and muscle tissue [ 85 , 86 ].…”