Influence of disc height and strain-dependent solute diffusivity on metabolic transport in patient-personalized intervertebral disc models
Introduction: Intervertebral disc (IVD) degeneration is a primary contributor to low back pain, with nutritional stress due to the IVD's avascularity recognized as a key factor. Solute transport within the disc relies predominantly on diffusion, which is governed by tissue morphology and me...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:dnet:recercat____::892d444b83625028c3197da2d1d43c7b |
| Acceso en línea: | https://hdl.handle.net/10230/73321 http://dx.doi.org/10.3389/fbioe.2025.1651786 |
| Access Level: | acceso abierto |
| Palabra clave: | Intervertebral disc Disc morphology Nutrient diffusion Disc material property Cell viability Patient-specific Patient-personalized Finite element |
| Sumario: | Introduction: Intervertebral disc (IVD) degeneration is a primary contributor to low back pain, with nutritional stress due to the IVD's avascularity recognized as a key factor. Solute transport within the disc relies predominantly on diffusion, which is governed by tissue morphology and mechanical deformation. However, the interplay between disc geometry, poro-mechanical strain, diffusion, and degeneration remains incompletely characterized. Previous specimen-specific models have captured inter-subject variability in metabolite transport, but the isolated effects of disc height and degeneration-dependent material composition have not been systematically assessed. Moreover, although strain-dependent diffusion coefficients are commonly modeled as porosity functions, the role of intra-element diffusivity gradients (Formula presented.), arising under large deformation, has been largely overlooked. Methods: The present study focuses on poro-mechanical finite element (FE) models of three patient-personalized L4-L5 lumbar IVD geometries, representing varying heights categorized as thin, medium, and tall IVDs. Three days of physiological mechanical load cycles, comprising 8 hours of rest and 16 hours of activity, were simulated, under both 'healthy' (Pfirrmann grade 1) and degenerated (Pfirrmann grade 3) tissue conditions. Results: Simulation outcomes demonstrated that a one-third reduction in disc height (relative to medium height) led to (Formula presented.) increases in oxygen and glucose concentrations and (Formula presented.) decreases in lactate levels, particularly in the nucleus and anterior regions. Conversely, a one-third height increase resulted in (Formula presented.) reductions in oxygen and glucose and a corresponding rise in lactate levels. These deviations were more pronounced in degenerated tissues, highlighting the synergistic role of morphology and matrix integrity in determining metabolic homeostasis. Importantly, the inclusion of (Formula presented.) in the diffusion-reaction model produced negligible changes in solute concentration profiles. Discussion: These findings underscore the predominant influence of disc geometry and matrix composition on IVD metabolic homeostasis, suggesting limited relevance of the (Formula presented.) term in practical simulations. Simplified diffusion models, without (Formula presented.), may be sufficient for future IVD mechano-transport FE modeling. |
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