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

Figure 2

Measuring points predicted with finite element (FE) model and lumbar kinematic analysis. (a) Left L4-5 vertebra (measuring points numbers 1 and 2). (b) Middle L4-5 vertebra (measuring points numbers 3, 4, and 7–10). (c) Right L4-5 vertebra (measuring points 5 and 6). (d) Posterior L4-5 vertebra (measuring points 11–14). (e) Measuring points used in Ti-24Nb-4Zr-8Sn pedicle screw group. (f) Measuring points used in Ti-6A1-4V pedicle screw group. Number 1 point for left pedicle screw fixed at outside the hole of the lumbar vertebrae; number 2 point for left pedicle screw fixed at outside the hole of the lumbar vertebrae; number 3 points for pedicle screw fixed at left side of the transverse of waist L4 vertebral body. Number 5 point for pedicle screw fixed at outside the hole of vertebral vertebrae; number 6 points for right pedicle screw fixed below the ground of the lumbar vertebrae; number 7 points for right pedicle screw fixed at transverse sites of lumbar vertebrae; number 8 points for right pedicle screw fixed at transverse process; number 9 point for right pedicle screw fixed at front of waist L4 vertebral body; number 10 point for right pedicle screw fixed on the 10th vertebrae of the lumbar vertebrae. Number 11 point was at the junction of left fixation rod and L4 pedicle screw. Number 12 point was at the junction of left fixation rod and L5 pedicle screw. Number 13 point was at the junction of right fixation rod and L4 pedicle screw. Number 14 point was at the junction of right fixation rod and L5 pedicle screw.

(a)

(b)

(c)

(d)

(e)

(f)