Table 1 Demographic data

Age (years)

60.59 ± 9.03

62.96 ± 8.59

0.294

Sex(M:F)

11:11

23:26

0.811^#

BMI (kg/m²)

25.28 ± 3.19

25.31 ± 3.78

0.975

Pre-op Pfi^◆(no.)

0.011^#

1

2

1

2

10

10

3

4

8

4

3

18

5

2

8

6

1

4

7

0

0

8

0

0

 Pre-op

52.93 ± 11.47

55.18 ± 10.62

0.426

 Last follow-up

17.38 ± 8.38

15.66 ± 4.29

0.265

 Pre-op

3.5 ± 3.16

3.24 ± 3.36

0.764

 Last follow-up

21.14 ± 3.53

21.06 ± 2.82

0.924

Fixed vertebrae (no.)

4.82 ± 1.00

4.22 ± 0.51

0.007*

Decompressed levels (no.)

2.36 ± 0.66

2.99 ± 0.72

0.001*

Interbody fusion (no.)

1.23 ± 0.92

2.00 ± 1.00

0.003*