Table 2 CT scan and radiographic parameters.

From: Low occupancy rate of the pedicle screw in the vertebral body leads to upper instrumented vertebral fracture

 

F (n = 58)

NF (n = 260)

P value

Cut-out of screw at UIV (%)

5 (8.6)

40 (15.4)

0.224

Not TK of 30°–39° (%)

55 (94.8)

214 (82.3)

0.001**

TAD; a (mm)

7.4 ± 3.9

7.1 ± 5.3

0.650

TAD; b (mm)

8.5 ± 4.3

8.6 ± 8.2

0.963

TAD; c (mm)

10.7 ± 3.6

8.4 ± 3.9

0.000***

TAD; d (mm)

10.5 ± 3.5

8.9 ± 3.9

0.003**

Total TAD; a + b + c + d (mm)

37.1 ± 9.0

32.9 ± 12.4

0.015*

APD (mm)

34.9 ± 3.8

36.2 ± 5.0

0.029*

ORPS (%)

69.7 ± 8.2

76.2 ± 9.5

0.000***

RVA (°)

− 3.4 ± 4.7

− 3.0 ± 5.6

0.595

SVA (°)

3.4 ± 4.0

2.2 ± 4.5

0.071

  1. Data are presented as n (%) or mean ± standard deviation.
  2. UIV upper instrumented vertebra, TAD tip-apex distance of pedicle screw, APD, anteroposterior diameter of vertebral body at UIV, ORPS occupancy rate of pedicle screw, RVA angle between rod contour and posterior wall of vertebral body, SVA angle between the direction of PS and upper endplate of UIV.
  3. *P < 0.05; **P < 0.01; ***P < 0.001.
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