In vitro and in silico characterization of open-cell structures of trabecular bone

Abstract

This work aimed to perform a detailed in vitro and in silico characterization of open-cell structures, which resemble trabecular bone, to elucidate osteoporosis failure mechanisms. Experimental and image-based computational methods were used to estimate Young's modulus and porosities of different open-cell structures (Sawbones; Malmö, Sweden). Three different open-cell structures with different porosities were characterized. Additionally, some open-cell structures were scanned using a microcomputed tomography system (μCT) to non-destructively predict specimen Young's modulus of the structures by developing voxel-based and tetrahedral finite element (FE) models. A 3D reconstruction and FE analyses were used. The experimental and computational results with different element types (linear and quadratic tetrahedrons and voxel-based meshes) were compared with Sawbones data (Sawbones; Malmö, Sweden) revealing important differences in Young's modulus and porosities. The specimens with high and low volume fractions were best represented by linear and quadratic tetrahedrons, respectively. These results could be used to develop new osteoporosis-prevention strategies.

Discrete particle model for cement infiltration within open-cell structures: Prevention of osteoporotic fracture

“…With respect to the limitations of the in silico characterization, to avoid the long computation times that can arise for more complex analyses [ 36 , 42 – 44 ], we have used smaller sub-regions to show the correlations between the experimental and computational results [ 34 ]. This approximation has resulted in errors as large as 9.5% in predictions of apparent stiffness [ 42 ].…”

“…A discrete particle model for cement infiltration based on the random-walk theory [ 33 ] is presented in this section ( Fig 1 ), and in vitro and in silico characterizations of augmented open-cell structures are described ( Fig 1 ). In vitro and in silico characterizations of non-augmented open-cell structures were performed in a previous study [ 34 ].…”

“…23 °C) and loaded in the direction of the axis of symmetry. The quasi-static compression load was measured with a commercial load cell (10 kN) applied at a constant velocity rate of 1 mm/min [ 34 ]. From the force-displacement curve, Young’s modulus of each specimen was estimated, and the increase in mechanical properties was calculated.…”

“…In silico characterization of non-augmented open-cell structures was previously conducted [ 34 ]. The obtained mean results are shown in Table 1 , and the process is revised in this work.…”

“…The interpolated images were reconstructed using a semiautomatic reconstruction (MIMICS, Materialise NV; Leuven, Belgium). The specimens were digitally cut, and a representative volume element was chosen [ 34 ]. A voxel mesh was generated using the voxel create mesh module (MIMICS, Materialise NV; Leuven, Belgium).…”