Table 1.
Material properties of the cervical finite element model
| Component | Element type | Constitutive model | Young’s modulus (MPa) | Poisson ratio | Reference |
|---|---|---|---|---|---|
| Cortical bone | C3D4 | Isotropic elastic | E = 10,000 | ν = 0.3 | 18 |
| C3D8 | |||||
| Cancellous bone | C3D4 | Neo-Hookean | E = 100 | ν = 0.3 | 20 |
| Annulus ground substance | C3D8H | Mooney-Rivlin | C10 = 0.1333, C01 = 0.0333, D1 = 0.6 | - | 20 |
| Annulus fibers | T3D2 | Hypeoelastic | 350–550 | ν = 0.3 | 17 |
| Nucleus pulposus | C3D8H | Mooney-Rivlin | C10 = 0.12, C01 = 0.09, D1 =0 | - | 13 |
| Spine ligaments (ALL, PLL, ISL, LF, CL) | Spring | Nonlinear elastic | - | - | 19 |
| PEEK cage | C3D4 | Linear elastic | E = 3,760 | ν = 0.38 | 17 |
| Screws/plate (titanium alloy) | C3D4 | Linear elastic | E = 110,000 | ν = 0.3 | 7 |
| PEEK ZOP device | C3D4 | Linear elastic | E = 3,760 | ν = 0.38 | 4, 17 |
| ZOP device screws (titanium alloy) | C3D4 | Linear elastic | E = 110,000 | ν = 0.3 | 7 |
| Bryan disc shell | C3D8 | Linear elastic | E = 110,000 | ν = 0.3 | 35 |
| Bryan disc Nucleus | C3D8 | Linear elastic | E = 30 | ν = 0.45 | 35 |
ALL, anterior longitudinal ligament; PLL, posterior longitudinal ligament; ISL, interspinous ligament; LF, ligamentum flavum; CL, capsular ligament; PEEK, polyetheretherketone; ZOP, zero-profile.