Table 2.

Methodological quality of studies included in the meta-analysis of cervical arthroplasty compared to ACDF for treating one-level CDDD

Years	Baseline			Randomization	Allocation concealment	Blinding	Quality level
	Size	Age	Sex
Porchet [7]	Comparable	Comparable	Comparable	Adequate	Unclear	Unclear	B
Murrey [8]	Comparable	Comparable	Comparable	Adequate	Unclear	Unclear	B
Nabhan [9]	Comparable	Comparable	Comparable	Adequate	Unclear	Unclear	B
Garrido [10]	Comparable	Comparable	Comparable	Adequate	Unclear	Unclear	B
Burkus [11]	Comparable	Comparable	Comparable	Adequate	Unclear	Unclear	B
Sasso [12]	Comparable	Comparable	Comparable	Adequate	Unclear	Double	B
Coric [13]	Comparable	Comparable	Comparable	Inadequate	Unclear	Single	B
Jawahar [14]	Comparable	Comparable	Comparable	Adequate	Unclear	Double	B

Comparable: the variables were comparable among all studies

Each domain of quality assessment was classified as: adequate (A), unclear (B), or inadequate (C)