Table 1 Demographic information

Number

12

14

Age (years)

53.4 ± 7.2

53.9 ± 7.4

Sex (M/F)

3/9

8/6

BMI (kg/m²)

23.9 ± 2.1

24.8 ± 1.7

BMD

0.3 ± 1.5

1.0 ± 1.6

Time to reoperation (years)

6.8 ± 3.4

8.4 ± 3.7

 One

5

2

 Two

6

10

 Three

1

2

 L1/2

0

1

 L2/3

4

2

 L3/4

6

8

 L4/5

2

2

 L5/S1

0

1

 Follow-up time (months)

15.5 ± 3.4

16.4 ± 4.2