Table 4.

Records of the changes of IDH, VBH, and ROM during the follow-up period

	Pre	1year	3year	6year
IDH (mm)	5.95 ± 0.22#∆	5.59 ± 0.40*∆	5.19 ± 0.31*#	4.73 ± 0.26*#∆
VBH (mm)	15.41 ± 1.68#∆	15.05 ± 1.65*∆	14.35 ± 1.64*#	13.67 ± 1.48*#∆
ROM (°)	52.46 ± 9.36#∆	58.91 ± 6.68*	58.71 ± 6.84*	59.26 ± 6.72*

Values are mean ± SD

*Compared with preoperative value, P < 0.05; #compared with postoperative value at 1year, P < 0.05; Δcompared with postoperative value at 3year, P < 0.05

Pre: preoperative; IDH: intervertebral disc height; VBH: vertebral body height; ROM: range of motion