Comparison between Groups I and II for VAS and NDI scores preoperatively and at 2 y postoperatively.
| Criteria | Group I (n = 192) | Group II (n = 112) | P Value |
| VAS, neck pain preoperatively | 81 mm (75; 86) | 82 mm (72; 94) | 0.16 |
| VAS, neck pain at 2 y postoperatively | 10 mm (9; 12) | 22 mm (12; 35) | 0.02 |
| NDI score preoperatively | 47.5 (42; 48) | 46 (43; 48) | 0.31 |
| NDI score at 2 y postoperatively | 12 (8; 14) | 18 (13; 27) | 0.01 |
Abbreviations: NDI, Neck Disability Index; VAS, visual analog scale.
Data presented as median (quartile 1; quartile 3).