Table 1 Detailed group information and postoperative results

Number of patients

54

60

Sex (male/female)

36/18

38/22

Age

75.6 (66-78)

80.5 (73 - 88)

Operation time

143 min

88 min

Blood loss

760 ml (510 - 1100 ml)

470 ml (320 - 580 ml)

Transfusion red cell units

1.88 (0 - 5)

0.35 (0 - 2)

ASA classification

Class I

0

9

Class II

35

31

Class III

19

20

Number of levels fused

1.5 (1 - 4)

1.8 (1 - 5)

Degenerative spinal stenosis

monosegmental

39

37

2 segments

6

7

3 segments

7

10

4 segments

2

3

5 segments

0

3

Length of hospital stay

12.6

13.1

Complications

Screw misplacement

1

0

Repeated decompression

2

1

Adjacent level disease

1

1

Pseudarthrosis

0

5

Fusion rate

41/54

46/60