Development of a continuum-based, meshless, finite element modeling approach for representation of trabecular bone indentation

• Published in: Journal of the mechanical behavior of biomedical materials Vol. 159; p. 106679
• Main Authors: Benais, Rémy, Rycman, Aleksander, McLachlin, Stewart D.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.11.2024
• Subjects: Aged; Biomechanical Phenomena; Bone Density; Cancellous Bone - diagnostic imaging; Cancellous Bone - physiology; Continuum-based modeling; Crushable foam; Female; Finite Element Analysis; Finite element model; Humans; Male; Marrow; Materials Testing; Mechanical Phenomena; Mechanical Tests; Smoothed particle hydrodynamics; Trabecular bone indentation; Smoothed particle hydrodynamics; Finite element model; Continuum-based modeling; Marrow; Crushable foam; Trabecular bone indentation
• ISSN: 1751-6161; 1878-0180; 1878-0180
• DOI: 10.1016/j.jmbbm.2024.106679

Implant subsidence into the underlying trabecular bone is a common problem in orthopaedic surgeries; however, the ability to pre-operatively predict implant subsidence remains limited. Current state-of-the-art computational models for predicting subsidence have issues addressing this clinical problem, often resulting from the size and complexity of existing subject-specific, image-based finite element (FE) models. The current study aimed to develop a simplified approach to FE modeling of subject-specific trabecular bone indentation resulting from implant penetration. Confined indentation experiments of human trabecular bone with flat- and sharp-tip indenters were simulated using FE analysis. A generalized continuum-level approach using a meshless smoothed particle hydrodynamics (SPH) approach and an isotropic crushable foam (CF) material model was developed for the trabecular bone specimens. Five FE models were generated with CF material parameters calibrated to cadaveric specimens spanning a range of bone mineral densities (BMD). Additionally, an alternative model configuration was developed that included consideration of bone marrow, with bone and marrow material parameters assigned to elements randomly according to bone volume (BV%) measurements of experimental specimens, owing to the non-uniform nature of trabecular bone tissue microstructure. Statistical analysis found significant correlation between the shapes of the numerical and experimental force-displacement curves. FE models accurately captured the bone densification patterns observed experimentally. Inclusion of marrow elements offered improved response prediction of the flat-tip indenter tests. Ultimately, the developed approach demonstrates the ability of a generalizable continuum-level SPH approach to capture bone variability using clinical bone imaging metrics without needing detailed image-based geometries, a significant step towards simplified subject-specific modeling of implant subsidence. [Display omitted] •Developed a continuum-based approach for modeling trabecular bone indentation.•Examined trabecular bone with marrow using smoothed particle hydrodynamics.•Crushable foam material accurately represented post-yield bone densification.•Model was adaptable to pre-clinical imaging metrics like bone mineral density.