Background
Methods
Intact model and unstable BI model
Components | Element type | Youngs Modulus(MPa) | Poisson’s Ratio |
---|---|---|---|
Cortical bone | C3D4 | 12,000 | 0.29 |
C3D8 | |||
Cancellous bone | C3D8 | 450 | 0.29 |
Cartilages | C3D8 | 10 | 0.3 |
Transverse ligament | 4-node membrane elements | 20 | 0.3 |
Cruciate ligament-vertical portion | T3D2 | 10 | 0.3 |
Alar ligament | T3D2 | 5 | 0.3 |
Apical ligament | T3D2 | 10 | 0.3 |
Anterior longitudinal ligament | T3D2 | 10 | 0.3 |
Anterior atlanto-occipital membrane | T3D2 | 10 | 0.3 |
Tectorial membrane | T3D2 | 10 | 0.3 |
Posterior atlanto-occipital membrane | T3D2 | 10 | 0.3 |
Posterior atlanto-axial membrane | T3D2 | 10 | 0.3 |
Joint capsules | T3D2 | 10 | 0.3 |
Cage | C3D8 | 3,600 | 0.25 |
Bone graft | C3D8 | 450 | 0.29 |
Screw or TARP (Ti-6Al-4 V) | C3D8 | 110,000 | 0.3 |
FEM of Cage + plate device
FEM of Cage + TARP device
Transoral surgical technique simulations
Interactions, loading and boundary conditions
Results
Validation of intact model and unstable BI model
Load case | Joint | Panjabi et al. [24] | Zhang et al. [15] | Intact model | Unstable BI model | |
---|---|---|---|---|---|---|
Flexion | C0-C1 | 3.5 ± 0.6 | 10.8–17.2 | 14.5 | 12.5 | - |
C1-C2 | 11.5 ± 2.0 | 9.8–16.2 | 15.0 | 12.5 | 16.9 | |
Extension | C0-C1 | 21.9 ± 1.9 | 10.8–17.2 | 13.3 | 16.7 | - |
C1-C2 | 10.9 ± 1.1 | 6.0–16.0 | 12.7 | 12.2 | 14.2 | |
Lateral bending | C0-C1 | 5.6 ± 0.7 | 2.6–8.6 | 5.5 | 3.7 | - |
C1-C2 | 4.0 ± 0.8 | 3.8–19.6 | 5.9 | 5.0 | 5.2 | |
Axial rotation | C0-C1 | 7.9 ± 0.6 | 1.0–10.5 | 8.5 | 8.3 | - |
C1-C2 | 38.3 ± 1.7 | 24.2–46.4 | 30.6 | 28.5 | 30.1 |