Mean angle of limitation of lateral bending

Mean angle of limitation of rotation

Mean angle of head tilt (ACM angle)

Preop.

Postop.

Differences

Preop.

Postop.

Differences

Preop.

Postop.

Differences

Variant 1

14.6

0.7

13.9

7.2

2.6

4.6

14.2

1.9

12.3

Variant 2

21.2

7.8

13.4

7.4

3.5

3.9

24.9

8.4

16.5

P value

0.042455

0.0858130

0.175734