Table 7 Results of the forest plots for the subgroup analysis for RCTs and non-RCTs

Number of patients with bone formation grade A at 12 months of follow-up

105

2

1.32

0.61, 2.86

0.48

0.49

0%

Random effect

Number of patients with bone formation grade B at 12 months of follow-up

105

2

1.13

0.46, 2.75

0.79

0.33

0%

Random effect

Number of patients with bone formation grade C at 12 months of follow-up

105

2

0.41

0.04, 4.20

0.45

0.07

71%

Random effect

Fusion rate at the 12-month follow-up

228

3

1.61

0.56, 4.67

0.38

0.18

42%

Random effect

Number of patients with VCF at the 12-month follow-up

105

2

0.07

0.01, 0.59

0.01

0.96

0%

Random effect

ODI at the 12-month follow-up

111

2

−1.61

−5.88, 2.67

0.46

0.03

78%

Random effect

Fusion rate at the 12-month follow-up

179

2

1.26

0.52, 3.05

0.62

0.46

0%

Random effect

Fusion rate at the 24-month follow-up

108

2

1.47

0.52, 4.13

0.47

0.21

36%

Random effect

Number of patients with VCF at 24-month follow-up

128

2

0.20

0.07, 0.58

0.003

0.54

0%

Random effect

Number of patients with pedicle screw loosening at the 24-month follow-up

128

2

0.25

0.09, 0.71

0.009

0.36

0%

Random effect