Table 1 Patient demographics and clinical characteristics

No. of patients

36

31

Age(year)

Male/Female

Weight(kg)

Height(cm)

BMI(kg/m²)

Hypertension(%)

DM(%)

58.53 ± 9.55

25/11

71.58 ± 12.35

167.69 ± 9.36

25.34 ± 3.11

12(33.3)

6(16.7)

59.97 ± 8.07

26/5

75.18 ± 10.45

167.90 ± 5.69

26.57 ± 2.66

13(41.9)

2(6.5)

0.511

0.167

0.207

0.455

0.089

0.468

0.270

Type of OPLL

0.873

 Continuous

 Segmental

 Mixed

7

16

13

5

13

13

Operation level

 C2/3/4/5

 C3/4/5/6

 C4/5/6/7

 C2/3/4/5/6

 C3/4/5/6/7

 C2/3/4/5/6/7

2

18

3

1

10

2

0

20

1

0

8

2

Mean

4.36

4.29

0.680

complications (N)

0

0

0.764

 Spinal cord injury

 C5 nerve palsy

 CSF leakage

 Screw looseness/failure

 Wound infection

 Postoperative Hematoma

4

0

0

1

0

140.89 ± 35.86

2

0

0

1

1

138.26 ± 39.07

Operation time (min)

330.83 ± 132.22

323.55 ± 146.25

0.840

Bleeding amount (ml)

0.739