Trabecular surface remodeling simulation for cancellous bone using microstructural voxel finite element models

A computational simulation method for three-dimensional trabecular surface remodeling was proposed, using voxel finite element models of cancellous bo ne, and was applied to the experimental data. In the simulation, the trabec ular microstructure was modeled based on digital images, and its morphologi cal changes due to surface movement at the trabecular level were directly e xpressed by removing/adding the voxel elements from/to the trabecular surfa ce. A remodeling simulation at the single trabecular level under uniaxial c ompressive loading demonstrated smooth morphological changes even though th e trabeculae were modeled with discrete voxel elements. Moreover the trabec ular axis rotated toward the loading direction with increasing stiffiness, simulating functional adaptation to the applied load. In the remodeling sim ulation at the trabecular structural level, a cancellous bone cube was mode led using a digital image obtained by microcomputed tomography (mu CT), and was uniaxially compressed. As a result, the apparent stiffness against the applied load increased by remodeling, in which the trabeculae reoriented t o the loading direction. In addition, changes in the structural indices of the trabecular architecture coincided qualitatively with previously publish ed experimental observations. Through these studies, it was demonstrated th at the newly proposed voxel simulation technique enables us to simulate the trabecular surface remodeling and to compare the results obtained using th is technique with the in vivo experimental data in the investigation of the adaptive bone remodeling phenomenon.