Table 2 Results of heterogeneity test, publication bias, and trim-and-fill analysis

VAS score at rest (8 h post-op)

7

614

− 1.08 [− 1.47, − 0.70]

89

< 0.0001

− 1.45

0.206

− 46.86

13.03

Stable

VAS score at rest (12 h post-op)

8

640

− 1.00 [− 1.43, − 0.58]

86

< 0.0001

− 2.76

0.033

− 22.31

− 1.33

Stable

VAS score at rest (24 h post-op)

9

754

− 0.56 [− 0.93, − 0.20]

89

0.002

− 1.57

0.16

− 27.52

5.55

Stable

VAS score at rest (48 h post-op)

10

874

− 0.62 [− 0.96, − 0.26]

93

0.0007

− 3.08

0.015

− 20.55

− 2.93

Stable

VAS score at rest (at discharge)

2

180

− 0.10 [− 0.28, 0.09]

0

0.31

NA

NA

NA

NA

Stable

VAS score at rest (overall)

10

3062

− 0.75 [− 0.96, − 0.53]

94

< 0.0001

VAS score with activity (8 h post-op)

4

300

− 0.83 [− 1.04, − 0.63]

0

< 0.0001

0.03

0.98

− 27.98

28.34

stable

VAS score with activity (12 h post-op)

6

460

− 0.72 [− 1.09, − 0.34]

79

0.0002

− 1.52

0.204

− 28.86

8.47

stable

VAS score with activity (24 h post-op)

6

460

− 0.53 [− 0.59, − 0.11]

79

0.01

− 2.04

0.111

− 27.05

4.13

Stable

VAS score with activity (48 h post-op)

6

460

− 0.61 [− 1.00, − 0.23]

78

0.002

− 2.79

0.049

− 26.04

− 0.07

Stable

VAS score with activity (at discharge)

2

180

− 0.15 [− 0.37, 0.07]

0

0.18

NA

NA

NA

NA

Stable

VAS score with activity (overall)

6

1860

− 0.61 [− 0.79, − 0.43]

76

< 0.0001

Cumulative morphine consumption (mg)

5

439

− 0.33 [− 0.52, − 0.14]

0

0.0007

− 0.56

0.617

− 15.96

11.21

Stable

ROM on POD1 (degree)

6

410

8.60 [5.13, 12.07]

76

< 0.0001

2.36

0.078

− 2.49

30.55

Stable

ROM on POD2 (degree)

7

550

8.04 [3.64, 12.44]

90

0.0003

1.35

0.233

− 9.54

30.82

Stable

ROM on POD3 (degree)

4

324

5.56 [0.37, 10.76]

84

0.04

4.38

0.048

0.23

24.62

Stable

ROM (overall)

9

1284

7.69 [5.18, 10.21]

86

< 0.0001

TUG test on POD1 (s)

4

353

− 3.32 [− 5.57, − 1.06]

18

0.004

− 0.85

0.487

− 23.08

15.49

Stable

TUG test on POD2 (s)

3

269

− 6.49 [− 12.02, − 0.96]

58

0.02

− 0.37

0.775

− 131.5

124.09

Stable

TUG test at discharge (s)

2

180

− 0.88 [− 4.20, 2.45]

0

0.61

NA

NA

NA

NA

Stable

TUG test (overall)

5

832

− 3.63 [− 5.74, − 1.52]

43

0.0008

walk distance on POD1 (meters)

5

439

0.23 [0.04, 0.41]

0

0.02

2.27

0.107

− 2.21

13.3

Unstable

Walk distance on POD2 (meters)

4

320

0.21 [− 0.01, 0.43]

0

0.06

5.01

0.038

1.1

14.47

Stable

Postoperative cumulative walk distance (meters)

2

233

0.48 [0.15, 0.82]

38

0.004

NA

NA

NA

NA

Stable

Walk distance (overall)

7

992

0.28 [0.15, 0.41]

2

< 0.0001

Quadriceps muscle strength on POD1

4

320

− 0.11 [− 0.24, 0.03]

0

0.13

− 1.49

0.276

− 26.21

12.76

Stable

Quadriceps muscle strength on POD2

4

320

− 0.04 [− 0.18, 0.09]

0

0.52

0.5

0.669

− 20.91

26.36

Stable

Postoperative quadriceps muscle strength (overall)

4

640

− 0.07 [− 0.17, 0.02]

0

0.13

Hospital stays (hour)

6

444

− 0.47 [− 0.78, − 0.16]

62

0.003

− 2.57

0.062

− 25.21

0.97

Stable

The incidence of PONV

6

440

0.62 [0.35, 1.09]

0

0.1

− 6.9

0.002

− 6.31

− 2.69

Stable