Table 2 Pre- and post-operative clinical scores and range of movement

 Pre-operative

5.9 ± 1.3

6.0 ± 1.6

6.3 ± 1.4

6.9 ± 1.4

 6-month post-operative

3.9 ± 1.4 ^a

3.4 ± 1.2 ^a

4.3 ± 1.1 ^a

4.0 ± 1.1 ^a

 12-month post-operative

2.4 ± 1.4 ^a,b

2.1 ± 1.3 ^a,b

3.3 ± 1.2 ^a,b,c

1.9 ± 1.0 ^a,b

 24-month post-operative

2.6 ± 1.5 ^a,b

2.1 ± 1.2 ^a,b

3.5 ± 1.4 ^a,e

2.2 ± 0.9 ^a,b

 Pre-operative

70.3 ± 6.2

65.9 ± 8.3

67.5 ± 4.8

63.2 ± 8.1

 6-month post-operative

77.3 ± 4.9 ^a

76.8 ± 6.5 ^a

73.8 ± 2.2 ^a

76.2 ± 8.6 ^a

 12-month post-operative

82.7 ± 6.0 ^a,b

86.2 ± 7.2 ^a,b

78.6 ± 2.8 ^a,b,c

85.9 ± 7.9 ^a,b

 24-month post-operative

81.4 ± 6.6 ^a,b

87.3 ± 7.3 ^a,b

75.3 ± 3.3 ^a,e

86.7 ± 7.4 ^a,b

  Extension angle (°)

− 3.7 ± 3.2

− 3.6 ± 1.8

− 3.4 ± 3.1

− 3.4 ± 2.1

  Flexion angle (°)

133.9 ± 9.8 ^d

123.6 ± 12.6

131.9 ± 8.2 ^d

117.7 ± 12.9

  Extension angle (°)

− 3.0 ± 1.6

—3.5±2.0

− 3.0 ± 2.0

− 3.5 ± 2.5

  Flexion angle (°)

134.9 ± 8.1

134.9±10.0 ^a

132.9 ± 8.5

135.3 ± 10.3 ^a