Experimental validation of a subject-specific finite element model of lumbar spine segment using digital image correlation

PLoS One. 2022 Sep 9;17(9):e0272529. doi: 10.1371/journal.pone.0272529. eCollection 2022.

Abstract

Pathologies such as cancer metastasis and osteoporosis strongly affect the mechanical properties of the vertebral bone and increase the risk of fragility fractures. The prediction of the fracture risk with a patient-specific model, directly generated from the diagnostic images of the patient, could help the clinician in the choice of the correct therapy to follow. But before such models can be used to support any clinical decision, their credibility must be demonstrated through verification, validation, and uncertainty quantification. In this study we describe a procedure for the generation of such patient-specific finite element models and present a first validation of the kinematics of the spine segment. Quantitative computed tomography images of a cadaveric lumbar spine segment presenting vertebral metastatic lesions were used to generate the model. The applied boundary conditions replicated a specific experimental test where the spine segment was loaded in compression-flexion. Model predictions in terms of vertebral surface displacements were compared against the full-field experimental displacements measured with Digital Image Correlation. A good agreement was obtained from the local comparison between experimental data and simulation results (R2 > 0.9 and RMSE% <8%). In conclusion, this work demonstrates the possibility to apply the developed modelling pipeline to predict the displacement field of human spine segment under physiological loading conditions, which is a first fundamental step in the credibility assessment of these clinical decision-support technology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomechanical Phenomena
  • Computer Simulation
  • Finite Element Analysis
  • Humans
  • Lumbar Vertebrae* / diagnostic imaging
  • Lumbar Vertebrae* / physiology
  • Lumbosacral Region
  • Spine* / physiology

Grants and funding

CG, MV: H2020 project “CompBioMed2: A Centre of Excellence in Computational Biomedicine” (topic INFRAEDI-02-2018, grant ID 823712, URL: https://www.compbiomed.eu/). MV: H2020 project “In Silico World: Lowering barriers to ubiquitous adoption of In Silico Trials” (topic SC1-DTH-06-2020, grant ID 101016503, URL: https://insilico.world/). MP: Marie Skłodowska-Curie Individual Fellowship (MetaSpine, MSCA-IF-EF-ST, 832430/2018, URL: https://ec.europa.eu/research/mariecurieactions/), the AOSpine Discovery and Innovation Awards (AOSDIA 2019_063_TUM_Palanca, URL: https://aospine.aofoundation.org/about-aospine/news/2019/2019_04-winners-2019-discovery-and-innovation-awards). LC: “Re-use with Love” (research grant year 2019, URL: https://www.reusewithlove.org/it/home/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.