Subject-Specific Modeling of Human Facet Capsular Ligament

Abstract

The research presented in this dissertation uses computational modeling to introduce a methodology of creating a hybrid microstructural-continuum, 3D, subject-specific model of the lower cervical spine. This model can demonstrates the importance of subject specificity on the tissue-level mechanical response of the cervical facet capsular ligament during flexion-extension, axial rotation, and lateral bending. As the first step towards this new modeling framework, I developed a structure-based continuum computational platform that uses the structural information of the macroscopically and/or microscopically heterogeneous tissues, such as facet capsular ligament, in a continuum-based finite element modeling and reduces the computational costs dramatically relative to discrete-fiber network multiscale models (Chapter 2). Next, I modified existing fiber-axon models to explore the effect of macroscopic strain rates, spanning a relevant range of values, on the viscoelastic micromechanical environment of an embedded neuron in reconstituted collagen gel (lower collagen concentration) and ex vivo tissue (higher collagen concentration) models (Chapter 3). Finally, anatomical and kinematic data of a 23-year-old participant, in combination with structural information from cadaveric facet capsular ligaments, were used to construct a hybrid microstructural-continuum subject-specific finite element model of the lower cervical spine as it undergoes various spinal motions, such as flexion-extension, lateral bending, axial rotation (Chapter 4).