Table 3.

Records of VAS and JOA score during the follow-up period

	Pre	1 month	1year	3year	6year
JOA	9.49 ± 2.16#∆	11.81 ± 1.80*∆	14.37 ± 1.65*#	15.39 ± 1.54*#∆	15.71 ± 1.13*#∆
VAS
Neck	6.34 ± 1.68#∆	3.51 ± 1.42*∆	2.05 ± 0.96*#	1.34 ± 0.80*#∆	1.02 ± 0.82*#∆
Arm	5.14 ± 1.48#∆	2.57 ± 1.31*∆	1.37 ± 0.91*#	0.83 ± 0.62*#∆	0.77 ± 0.76*#∆

Values are mean ± SD

* Compared with preoperative value, P < 0.05; # compared with postoperative value at 1 month, P < 0.05; Δ compared with postoperative value at 1year, P < 0.05

Pre: preoperative; VAS: visual analog scale; JOA: Japanese Orthopedic Association