Table 1 Material properties of elements used in the model
Element group name | Element type | Young’s Modulus (MPa) | Poisson's ratio |
|---|---|---|---|
Cortical bone | Isotropic, elastic hex elements (C3D8) | 10,000 | 0.3 |
Cancellous bone | Isotropic, elastic hex elements (C3D8) | 450 | 0.25 |
Posterior bone | Isotropic, elastic hex elements (C3D8) | 3500 | 0.25 |
Annulus ground substance | Isotropic, elastic hex elements (C3D8) | 4.2 | 0.25 |
Annulus fibers | REBAR elements | - | 0.45 |
Nucleus pulposus | Incompressible fluid, cavity elements | 1 | 0.49 |
Anterior Longitudinal Ligament (ALL) | Tension-only, Truss elements (T3D2) | 15 (<12%*) 30 (>12%*) | 0.3 |
Posterior Longitudinal Ligament (PLL) | Tension-only, Truss elements (T3D2) | 10 (<12%*) 20 (>12%*) | 0.3 |
Ligamentum Flavum (LF) | Tension-only, Truss elements (T3D2) | 7 (<12%*) 30 (>12%*) | 0.3 |
Interspinous Ligament (ISL) | Tension-only, Truss elements (T3D2) | 5(<25%*) 10 (>25%*) | 0.3 |
Capsular Ligaments (CAP) | Tension-only, Truss elements (T3D2) | 15 (20-40%*) 30 (>40%*) | 0.3 |
T itanium (InterPlate) | Isotropic, elastic Tetrahedral elements (C3D4) | 1,130,000 | 0.34 |
Cortical Bone Graft | Isotropic, elastic Tetrahedral elements (C3D4) | 10,000 | 0.3 |
PEEK (InterPlate) | Isotropic, elastic Tetrahedral elements (C3D4) | 3400 | 0.4 |