Evaluation of a Porous Bioabsorbable Interbody Mg-Zn Alloy Cage in a Goat Cervical Spine Model
Table 4
Stiffness of the segments treated with two types of implants (bone graft versus cage) in the 3 anatomical axes.
3 wk
6 wk
12 wk
24 wk
Flexion (N·m/mm)
Cage
0.52 ± 0.21
0.68 ± 0.25
0.70 ± 0.26
1.06 ± 0.28
Bone
0.58 ± 0.26
1.01 ± 0.48
1.40 ± 0.24
2.42 ± 0.59
Extension (N·m/mm)
Cage
0.35 ± 0.10
0.54 ± 0.18
0.62 ± 0.30
0.79 ± 0.14
Bone
0.43 ± 0.15
0.51 ± 0.27
1.06 ± 0.39
1.69 ± 0.42
Lateral bending (left) (N·m/mm)
Cage
0.30 ± 0.04
0.45 ± 0.27
0.62 ± 0.18
0.77 ± 0.37
Bone
0.26 ± 0.07
0.55 ± 0.18
1.23 ± 0.29
2.31 ± 0.60
Lateral bending (right) (N·m/mm)
Cage
0.34 ± 0.12
0.46 ± 0.23
0.77 ± 0.24
0.71 ± 0.29
Bone
0.45 ± 0.06
0.64 ± 0.21
1.10 ± 0.34
1.94 ± 0.55
Axial rotation (left) (N·m/°)
Cage
0.22 ± 0.07
0.39 ± 0.17
0.44 ± 0.23
0.48 ± 0.14
Bone
0.30 ± 0.12
0.53 ± 0.25
0.71 ± 0.13
1.18 ± 0.13
Axial rotation (right) (N·m/°)
Cage
0.21 ± 0.07
0.39 ± 0.18
0.57 ± 0.17
0.51 ± 0.15
Bone
0.38 ± 0.19
0.74 ± 0.30
0.69 ± 0.23
1.09 ± 0.20
Statistically significant differences between two types of implants ( = 0.05) are marked by boldface text (: p < 0.05; : p < 0.01; : p < 0.001; : p < 0.0001, independent-sample t-test).
