Biomechanical Effect of Disc Height on the Components of the Lumbar Column at the Same Axial Load: A Finite-Element Study
Table 3
The von-Mises stress on the structures of the L4‐5 spine in the extension mode when the disc height was reduced to 75% and 50% compared to normal (100%).
Component
The 50% anterior disc model, MPa (a)
The 75% anterior disc model, MPa (b)
The 100% anterior disc model, MPa (c)
Rate of change [(a-c)/c ∗ 100] (%)
The 50% posterior disc model, MPa (d)
The 75% posterior disc model, MPa (e)
The 100% posterior disc model, MPa (f)
Rate of change [(d-f)/f ∗ 100] (%)
Cortical bone
L4
1.5655
1.6992
1.8453
−15.16
2.1541
1.9900
1.8453
16.73∗
L5
1.0263
1.0463
1.0692
−4.01
1.2675
1.1655
1.0692
18.55∗
Cancellous bone
L4
0.0816
0.0803
0.0809
0.92∗
0.0881
0.0853
0.0809
8.92∗
L5
0.1007
0.0963
0.0926
8.66∗
0.0982
0.0953
0.0926
6.05∗
Posterior bone
L4
0.5631
0.6448
0.7204
−21.83
0.7227
0.7293
0.7204
0.32∗
L5
0.6623
0.6795
0.6970
−4.97
0.7354
0.7169
0.6970
5.51∗
Endplate (upper)
L4-5
1.4776
1.7772
2.0771
−28.86
2.2418
2.1836
2.0771
7.93∗
Endplate (lower)
L4-5
0.5666
0.6428
0.7180
−21.08
0.8999
0.8127
0.7180
25.34∗
Disc (outer)
L4-5
0.1739
0.1857
0.1972
−11.79
0.2124
0.2095
0.1972
7.71∗
Disc (inner)
L4-5
0.0371
0.0438
0.0481
−22.80
0.0522
0.0516
0.0481
8.61∗
∗ indicates that a larger load than normal was received when the disc height was reduced by 50%.
