n (%)

Total

1-level stenosis

C2-3: 4 (6.1)

24 (36.9)

C3-4: 10 (15.3)

C4-5: 3 (10.7)

C5-6: 4 (6.1)

C6-7: 2 (3)

C6: 1 (1.5)

2-level stenosis

C2-4: 1 (1.5)

21 (32.3)

C3-5: 9 (13.8)

C4-6: 4 (6.1)

C5-7: 6 (9.2)

C3-4, C6-7: 1 (1.5)

3-level stenosis

C2-5: 2 (3.1)

12 (18.5)

C3-6: 9 (13.8)

C4-7: 1 (1.5)

4-level stenosis

C2-6: 1 (1.5)

8 (12.3)

C3-7: 6 (9.2)

C4-6: 1 (1.5)