Table 1 Demographics and clinical characteristics of patients at the surgery

Age, years

67.5 ± 11.7

Male sex

30 (65.2)

Revised Tokuhashi score, points

6.6 ± 2.5

New Katagiri score, points

4.7 ± 2.0

SINS, points

11.4 ± 2.7

 Grades 0 and 1

14 (30.4)

 Grades 2 and 3

32 (69.6)

 Upper cervical spine

9 (19.6)

 Middle cervical spine

18 (39.1)

 Cervicothoracic junction

19 (41.3)

 PS 1

2 (4.3)

 PS 2

10 (21.7)

 PS 3

22 (47.8)

 PS 4

12 (26.1)

EQ5D, points

0.085 ± 0.487

 Grades A and B

1 (2.2)

 Grades C and D

29 (63.0)

 Grade E

16 (34.8)

Operative time, min

188.8 ± 71.2

Blood loss, g

276.8 ± 301.1

Number of fixed vertebrae

5.8 ± 2.8