Table 2 The material properties of the spinal soft tissues and hard tissues used in the finite element model
Description | Element Type | Young’s Modulus (MPa) | Poisson’s Ratio |
|---|---|---|---|
Cortical bone | 3-noded triangular shell | 12,000 | 0.3 |
Cancellous bone | 4-noded tetrahedron | 100 | 0.2 |
Posterior elements | 4-noded tetrahedron | 3500 | 0.25 |
Facet cartilage | 4-noded tetrahedron | 10.4 | 0.4 |
End plate | 4-noded tetrahedron | 600 | 0.3 |
Nucleus pulposus | 8-noded brick | 1 | 0.49 |
Annulus ground substance | 8-noded brick | 3.4 | 0.4 |
Annulus fibers | Truss (tension-only) | 450 | 0.45 |
Titanium plate | 4-noded tetrahedron | 120,000 | 0.3 |
Titanium screw | 4-noded tetrahedron | 120,000 | 0.3 |