Table 1.
Material properties used in finite element model of lumbar spine
|
Bony structures |
Young’s modulus |
Poisson’s |
Reference |
|
|---|---|---|---|---|
| E (MPa) | ratio | |||
| Cortical bone |
12,000 |
0.3 |
Shirazi et al. [7] |
|
| Cancellous bone |
100 |
0.2 |
||
| Posterior element |
3,500 |
0.25 |
||
| End plate |
25 |
0.25 |
Sharma et al. [8] |
|
| Annulus ground |
4.2 |
0.45 |
||
| Nucleus pulposus |
1.0 |
0.499 (incompressible) |
Goel et al. [6] |
|
|
Annulus fibers |
Young’s modulus |
Cross-sectional |
Reference |
|
|
E (MPa) |
Area (mm2) |
|||
| Layer 1/2 |
550 |
0.50 |
Combined from Shirazi et al. [7] and Smit et al. [5] |
|
| Layer 3/4 |
495 |
0.39 |
||
| Layer 5/6 |
413 |
0.31 |
||
| Layer 7/8 |
358 |
0.24 |
||
|
Ligaments |
Young’s modulus |
Cross-sectional |
Reference |
|
|
E (MPa) |
Area (mm2) |
|||
| ALL |
7.8 (<12%) |
20 (>12%) |
63.7 |
Adapted from Goel et al. [6] |
| PLL |
10 (<11%) |
20 (>11%) |
20 |
|
| LF |
15 (<6.2%) |
19 (>6.2%) |
40 |
|
| CL |
7.5 (<25%) |
33 (>25%) |
30 |
|
| ITL |
10 (<18%) |
59 (>18%) |
1.8 |
|
| ISL |
10 (<14%) |
12 (>14%) |
40 |
|
| SSL | 8 (<20%) | 15 (>20%) | 30 | |
Abbreviations: All anterior longitudinal ligament, PLL posterior longitudinal ligament, LF ligamentum flavum, CL capsular ligament, ITL intertansverse ligament, ISL interspinous ligament, SSL supraspinous ligament.