Table 1 Material properties defined in the T12-L2 FE model (ALL, anterior longitudinal ligament; PLL, posterior longitudinal ligament; LF, ligamentum flavum; ISL, interspinous ligament; supraspinous ligament, SSL; intertransverse ligament, ITL; CL, cystic ligament)
Component | Young’s modulus (MPa) | Poisson’s ratio | Cross-sectional area (mm2) |
|---|---|---|---|
Bony structures | |||
Cortical bone | Osteoporotic:8040 (67% of normal) Normal:12,000 | 0.3 | - |
Cancellous bone | Osteoporotic:34 (34% of normal) Normal:100 | 0.2 | - |
Posterior structure | Osteoporotic:2345(67% of normal) Normal:3500 | 0.3 | - |
Endplate | Osteoporotic:670(67% of normal) Normal:1000 | 0.4 | - |
Facet cartilage | 10 | 0.4 | - |
Intervertebral disc | |||
Annulus fibre | 450 | 0.45 | 0.15 |
Annulus ground | 4.2 | 0.45 | - |
Nucleus pulposus | 1 | 0.49 | - |
Ligaments | |||
ALL | 12.8 | - | 63.7 |
PLL | 7 | - | 20 |
LF | 3 | - | 40 |
ISL | 6 | - | 40 |
SSL | 6.6 | - | 30 |
ITL | 7 | - | 1.8 |
CL | 4 | - | 30 |
Implants | |||
Ti | 110,000 | 0.3 | - |
PMMA | 3500 | 0.3 | - |