Table 2 Range of motion

Flexion (°)

    at 6 weeks

73\(\pm\)21

74\(\pm\)27

80 (30)

80 (40)

0.002 (0.01, 0.33)

0.510

    at 3 months

115\(\pm\)25

101\(\pm\)30

120 (40)

100 (25)

0.21 (0.01, 0.49)

0.080

    at 6 months

138\(\pm\)28

130\(\pm\)29

150 (40)

130 (41)

0.13 (0.01, 0.44)

0.140

    at 12 months

143\(\pm\)27

134\(\pm\)35

150 (20)

140 (20)

0.14 (0.01, 0.48)

0.130

    at 21 months

146\(\pm\)26

139\(\pm\)39

155 (25)

150 (30)

0.004 (0.001, 0.4)

0.322

Abduction (°)

    at 6 weeks

66\(\pm\)17

65\(\pm\)26

70 (30)

50 (40)

0.06 (0.01, 0.39)

0.358

    at 3 months

103\(\pm\)26

89\(\pm\)25

100 (30)

90 (20)

0.27 (0.02, 0.54)

0.036

    at 6 months

131\(\pm\)32

116\(\pm\)29

135 (40)

110 (50)

0.24 (0.02, 0.52)

0.049

    at 12 months

137\(\pm\)33

122\(\pm\)33

150 (25)

120 (38)

0.27 (0.02, 0.62)

0.049

    at 21 months

147\(\pm\)29

126\(\pm\)42

158 (26)

141 (41)

0.31 (0.04, 0.64)

0.058

External rotation (°)

    at 6 weeks

14\(\pm\)20

3\(\pm\)10

10 (23)

0 (10)

0.36 (0.03, 0.68)

0.032

    at 3 months

33\(\pm\)16

18\(\pm\)21

30 (25)

15 (30)

0.36 (0.08, 0.60)

0.010

    at 6 months

45\(\pm\)15

33\(\pm\)18

45 (23)

30 (30)

0.32 (0.07, 0.56)

0.016

    at 12 months

49\(\pm\)13

45\(\pm\)17

45 (25)

50 (25)

0.06 (0.01, 0.42)

0.380

    at 21 months

57\(\pm\)14

51\(\pm\)24

55 (15)

55 (11)

0.01 (0.01, 0.41)

0.539

Internal rotation (1–20)

    at 6 weeks

4\(\pm\)4

3\(\pm\)2

2 (1)

2 (1)

0.14 (0.01, 0.52)

0.270

    at 3 months

5\(\pm\)4

5\(\pm\)3

4 (1)

4 (5)

0.13 (0.01, 0.47)

0.773

    at 6 months

8\(\pm\)4

6\(\pm\)4

8 (9)

5 (5)

0.25 (0.01, 0.52)

0.060

    at 12 months

10\(\pm\)4

8\(\pm\)4

10 (7)

9 (6)

0.20 (0.01, 0.52)

0.139

    at 21 months

11\(\pm\)5

10\(\pm\)4

11 (6)

11 (7)

0.1 (0.01, 0.48)

0.312