Table 1 Differences of baseline and surgical characteristics between two groups

Age (year)

66.62 ± 2.36

65.02 ± 2.35

0.63

Sex (male/female)

25/20

24/23

0.67

Height (m)

1.65 ± 0.01

1.64 ± 0.01

0.28

Weight (Kg)

72.47 ± 1.62

69.93 ± 2.21

0.36

BMI (Kg/m²)

26.21 ± 0.38

25.81 ± 0.69

0.62

Diagnosis

 Spinal stenosis

22

18

 Fracture

12

18

 Spondylolisthesis

10

10

 Scoliosis

1

1

0.24

Operating time (min)

47.45 ± 3.99

39.26 ± 2.60

0.09

(Planning and screw setting)

Bleeding volume (ml)

128.80 ± 15.20

96.23 ± 10.47

0.08

(Single segment)

Screw satisfaction

97.50%

92.60%

 < 0.01*

(A + B)/(A + B + C + D) × 100%

Length of hospital stay  after surgery (day)

12.49 ± 1.12

12.81 ± 0.80

0.82

Complications

 Infection

2

4

 Revision

0

1

0.41

Medical group

 Group.1

20

17

 Group.2

15

19

 Group.3

10

11

0.68