Table 4 Pre- and postoperative parameters in the 4 subgroups

C2-7 angle (°)

−18.9 ± 11.4

−24.9 ± 13.6

0.158

7.6 ± 7.3

−7.0 ± 8.5

0.001^a

−12.4 ± 8.3

5.9 ± 4.5

0.001^a

15.3 ± 10.5

11.9 ± 8.0

0.173

TIA (°)

82.5 ± 14.5

82.8 ± 14.6

0.783

66.9 ± 7.4

67.9 ± 7.0

0.578

68.5 ± 9.7

65.9 ± 10.7

0.012^a

61.1 ± 7.3

61.5 ± 6.1

0.707

T1 slope (°)

25.0 ± 12.2

29.1 ± 7.6

0.193

11.0 ± 7.5

16.8 ± 6.7

0.016^a

16.7 ± 5.1

14.0 ± 2.8

0.057

7.6 ± 6.5

11.0 ± 5.8

0.056

C2-7 SVA (cm)

1.7 ± 1.6

1.7 ± 1.6

0.942

1.9 ± 0.9

1.6 ± 0.8

0.255

1.3 ± 0.4

1.7 ± 0.4

0.075

2.0 ± 0.6

2.1 ± 0.6

0.378

PTK (°)

13.6 ± 11.8

28.9 ± 10.4

0.001^a

2.6 ± 8.1

16.8 ± 6.6

0.000^a

12.4 ± 5.5

8.5 ± 3.1

0.040^a

5.5 ± 8.2

9.0 ± 6.9

0.052

TK (°)

38.8 ± 24.0

18.9 ± 4.1

0.044^a

26.3 ± 16.4

16.5 ± 4.7

0.031^a

24.5 ± 13.2

12.8 ± 3.0

0.045^a

18.1 ± 8.0

14.8 ± 6.2

0.043^a

LL (°)

−65.3 ± 18.0

−47.1 ± 7.3

0.008^a

−56.2 ± 14.5

−50.4 ± 8.5

0.106

−58.7 ± 11.3

−53.5 ± 13.7

0.462

−45.6 ± 10.3

−49.2 ± 10.3

0.157

Cobb (°)

59.3 ± 12.3

10.6 ± 5.1

0.000^a

50.2 ± 12.1

9.0 ± 8.9

0.000

47.0 ± 7.2

6.1 ± 2.8

0.000^a

50.6 ± 7.8

6.4 ± 3.8

0.000^a