Table 5 Certainty of evidence per outcome category (GRADE)

Joint and muscle function (Knee ROM, flexion, in °)

Very Low

 Anneli (2017) [32]

150

120

30 (+ 25%)

 Bade (2017) [33]

126

126

0 (0%)

 Codine (2004)^a [37]

22.32

6.25

16.07 (+ 257%)

 Eisermann (2004)^a [38]

10.4

9.4

1(+ 10%)

 Frost (2002) [39]

102

102

0 (0%)

 Han (2015) [40]

96.8

95.7

1.1 (+ 1%)

 Jacksteit (2021) [44]

113.77

110.33

3.44 (+ 3%)

 Liao, Chiu (2020)^a [48]

28.08

20.58

7.5 (+ 36%)

 Li (2019) [52]

112.1

110

2.1 (+ 2%)

 Mockford (2008) [54]

107.9

106.6

1.3 (+ 1%)

 Sano (2018) [59]

119.1

121.1

2 (+ 2%)

 Schache (2019) [60]

120

117

3 (3%)

 Teissier (2020) [62]

18

10

8 (80%)

 Vuorenmaa (2014) [64]

14.4

14.2

0.2 (+ 1%)

 Functional performance (TUG)^b

Very low

 Bade (2017) [33]

17.20

16.41

0.79 (+ 5%)

 Hardt (2018) [41]

12.1

17.8

-5.7 (-32%)

 Jacksteit (2021) [44]

8.82

10.18

-1.36 (-13%)

 Liao, Tsauo (2020) [51]

9.13

12.32

-3.19 (-26%)

 Roig-Casasús (2018) [58]

14.4

17.3

-2.9 (-17%)

 Sano (2018) [59]

10.44

12.22

-1.78 (-15%)

 Schache (2019) [60]

8

8

0 (0%)

 Vuorenmaa (2014) [64]

-1.58

-0.43

-1.15 (-73%)

 Participation (WOMAC, pain)^b

Very low

 Han (2015) [40]

7.2

7.4

-0.2 (-3%)

 Lenssen (2006) [47]

9.2

8.3

0.9 (+ 10%)

 Liao (2015) [49]

22.4

22.4

0 (0%)

 Liao, Chiu (2020)^a [48]

-6.95

-5.55

1.4 (20%)

 Liao, Tsauo (2020) [51]

9.1

9.3

-0.2 (-2%)

 Li (2019) [52]

9.1

9.3

-0.2 (-2%)

 Moffet (2004) [55]

9.4

11.8

-2.4 (-26%)

 Piva (2010)^a [56]

-30

-27

3 (+ 10%)

 Vuorenmaa (2014)^a [64]

-15

-14

1 (+ 7%)