Anterior Cervical Discectomy and Fusion Using Zero-P System for Treatment of Cervical Spondylosis: A Meta-Analysis

Table 1

Quality evaluation of RCT.

First author and author (year of publication)	Country	Type of study	Surgical segment	Sample size		Gender (M/F)		Age (x ± s, years)		Follow-up time (x ± s)
				Zero-P	PC	Zero-P	PC	Zero-P	PC	Zero-P	PC
Li et al. (2015) [12]	China	Randomized controlled trial	1	12	11	7/5	5/6	50.3 ± 8.8	51.1 ± 6.7	24	24
He et al. (2018) [11]	China	Randomized controlled trial	2	52	52	28/24	27/25	55.4 ± 12.4	59.5 ± 12.6	24	24
Yan and Nie (2018) [15]	China	Randomized controlled trial	1	49	49	29/20	29/20	43.1 ± 5.3	43.3 ± 5.2	12	12
Chen et al. (2016) [10]	China	Randomized controlled trial	3	34	38	21/13	25/13	56.9 ± 5.9	56.2 ± 5.7	12	12
Qizhi et al. (2016) [13]	China	Randomized controlled trial	2	16	14	11/5	9/5	48.13 ± 5.98	46.79 ± 5.15	32.4	32.4
Scholz et al. (2020) [14]	Germany	Randomized controlled trial	1	21	20	13/8	11/9	58	58	24	24
Alimi et al. (2016) [16]	United States	Nonrandomized retrospective study	1, 2, 3	69	35	35/34	18/17	58.2 ± 1.45	51.5 ± 1.95	15.7 ± 1.23	14.8 ± 2.13
Li et al. (2017) [18]	China	Nonrandomized retrospective study	1, 2, 3, 4	68	70	41/27	45/25	50.6 ± 7.5	51.3 ± 7.9	29.7 ± 6.5	30.8 ± 6.6
Liu et al. (2016) [19]	China	Nonrandomized retrospective study	3, 4	28	32	10/18	12/20	56.6 ± 9.7	57.5 ± 9.5	23.3 ± 6.9	24.2 ± 6.4
Cho et al. (2015) [17]	Korea	Nonrandomized retrospective study	1	21	29	12/9	19/10	56.1 ± 12	55.2 ± 10.4	24	24
Shi et al. (2016) [21]	China	Nonrandomized retrospective study	1	68	60	33/35	24/36	47.4 ± 7.0	46.5 ± 6.8	48	48
Sun et al. (2020) [22]	China	Nonrandomized retrospective study	3	27	34	15/12	25/9	54.7 ± 7.6	56.4 ± 7.5	60	60
Wang et al. (2014) [23]	China	Nonrandomized retrospective study	1, 2	30	33	18/12	14/19	56.8 ± 11.0	54.0 ± 10.0	24.1 ± 7.8	23.8 ± 8.2
Yang et al. (2015) [24]	China	Nonrandomized retrospective study	1, 2, 3	30	32	20/10	22/10	44.1 ± 5.8	42.8 ± 6.1	30.6 ± 2.4	33.1 ± 3.0
Shen et al. (2018) [20]	China	Nonrandomized retrospective study	1, 2, 3	27	31	16/11	14/17	52.3 ± 9.2	54.7 ± 9.2	37.2 ± 22.8	46.8 ± 21.6
Yun et al. (2016) [25]	Korea	Nonrandomized retrospective study	3	31	32	29/3	22/9	53.29 ± 7.55	54.18 ± 9.87	12.77 ± 7.85	13.62 ± 9.21
Zhang et al. (2016) [26]	China	Nonrandomized retrospective study	1, 2	22	27	11/12	13/14	48.6 ± 8.1	52.7 ± 8.3	24	24