Table 1 Patient demographics

Sample size

95

95

Age (years)

72.39 ± 6.12

70.81 ± 6.27

0.12

Male/female

45/50

40/55

0.47

Body mass index

25.67 ± 3.32

25.73 ± 4.00

0.93

Smoker

3

5

0.25

 Hypertension

68

74

0.32

 Heart disease

26

24

0.74

 Chronic lung disease

0

2

0.16

 Diabetes

24

31

0.26

 Osteoporosis

16

15

0.84

 Gastrointestinal

8

5

0.39

 Psychological symptoms

3

2

0.65

 Preoperative JOA

8.30 ± 2.11

8,12 ± 1.90

0.59

 Preoperative ODI, %

60.89 ± 11.88

58.88 ± 8.26

0.55

 Preoperative VAS (back)

7.15 ± 0.72

7.01 ± 0.70

0.25

 Preoperative VAS (leg)

7.06 ± 0.63

7.09 ± 0.59

0.56

 I

13

10

 II

68

73

 III

14

12

 IV

0

0

 1

44

40

0.56

 2

51

55

0.56

Operative time

186.78 ± 57.38

198.72 ± 69.48

0.58

Intraoperative blood loss

283.38 ± 195.44

311.51 ± 219.44

0.42