Research Article

Ti-24Nb-4Zr-8Sn Alloy Pedicle Screw Improves Internal Vertebral Fixation by Reducing Stress-Shielding Effects in a Porcine Model

Table 6

The stress resistance of Ti-24Nb-4Zr-8Sn and Ti-6A1-4V fixation groups under backward flexion loading after fixation (MPa).

Measuring pointsSample 1Sample 2Sample 3Sample 4Sample 5Sample 6Mean ± SD

1
 EG−4.7−4.88−4.78−4.93−5.01−4.95−4.88 ± 0.15
 RG−5.95−5.86−6.12−5.84−6.11−5.78−5.94 ± 0.13
2
 EG−4.82−4.99−4.93−4.78−4.9−4.86−4.88 ± 0.07
 RG−6.16−6.09−5.88−6.14−5.93−5.86−6.01 ± 0.14
3
 EG−2.09−2.44−2.5−2.32−2.48−2.36−2.37 ± 0.15
 RG−1.77−1.84−1.71−1.73−1.69−1.75−1.75 ± 0.05
4
 EG−2.32−2.36−2.05−2.19−2.4−2.11−2.24 ± 0.14
 RG−1.67−1.88−1.63−1.77−1.84−1.79−1.76 ± 0.10
5
 EG−4.99−4.88−4.93−4.78−5.03−4.9−4.92 ± 0.09
 RG−6.03−6.16−6.09−5.86−6.16−6.11−6.07 ± 0.11
6
 EG−4.93−4.76−5.05−4.72−4.8−4.97−4.87 ± 0.13
 RG−5.93−5.89−5.99−6.11−6.09−5.97−6.00 ± 0.09
7
 EG−2.38−2.19−2.52−2.09−2.36−2.34−2.31 ± 0.15
 RG−1.67−1.61−1.82−1.86−1.69−1.79−1.74 ± 0.10
8
 EG−2.44−2.09−2.46−2.25−2.4−2.3−2.32 ± 0.14
 RG−1.8−1.71−1.73−1.79−1.86−1.63−1.75 ± 0.08
9
 EG−1.67−1.59−1.75−1.57−1.69−1.73−1.67 ± 0.07
 RG−1.88−2.25−2−2.25−1.98−2.28−2.11 ± 0.17
10
 EG−1.57−1.73−1.67−1.61−1.56−1.71−1.64 ± 0.07
 RG−2.02−2.11−2.09−2.32−2.02−2.19−2.13 ± 0.11
11
 EG−11.74−11.56−12.57−12.33−12.39−12.21−12.13 ± 0.40
 RG−15.95−16.61−17.05−16.5−17.93−17.38−16.90 ± 0.70
12
 EG−12.45−12.21−11.68−12.45−12.8−12.15−12.29 ± 0.38
 RG−17.16−16.28−17.71−17.27−16.83−16.28−16.92 ± 0.57
13
 EG−11.62−13.04−12.33−12.74−12.04−12.86−12.44 ± 0.54
 RG−16.83−16.17−17.82−16.17−18.15−16.94−17.01 ± 0.83
14
 EG−12.04−11.98−12.74−12.98−12.33−12.8−12.48 ± 0.42
 RG−17.6−17.05−16.83−17.16−17.71−16.06−17.07 ± 0.60

Note.  versus an RG group. Stress values are negative due to compressive pressure caused by backward flexion load.