Table 1.

Characteristics of the included studies

Study	Intervention		Sample size		Mean age (years)		Sex (male/female)		Missing data
	CDA	ACDF	CDA	ACDF	CDA	ACDF	CDA	ACDF	CDA	ACDF
Park et al. [33]	PCM	ACDF with allograft and plate	272	182	45	44.0	NR		NR
Nabhan et al. [30]	ProDisc-C	ACDF with Solis cage and ABC plate	10	10	NR		13/7		0	0
Mummaneni et al. [26]	Prestige ST	ACDF with allograft and Atlantis System	276	265	43	43.9	128/148	122/143	53	67
Riina et al. [36]	Prestige ST	ACDF with allograft and Atlantis plate	10	9	41	38.1	2/8	3/6	1	2
Heller et al. [17]	Bryan	ACDF with allograft and plate	242	221	44	44.7	110/132	113/108	12	27
Murrey et al. [28]	ProDisc-C	ACDF with allograft and angle plate	103	106	42	43.5	46/57	49/57	2	6
Coric et al. [8]	Kineflex|C	ACDF	136	133	44	43.9	51/85	59/74	17	18
Zhang et al. [48]	Bryan	ACDF with allograft and plate	60	60	45	45.6	35/25	32/28	4	7
Nabhan et al. [31]	ProDisc-C	ACDF with Solis cage and plate	25	24	44		NR		9
Cheng et al. [7]	Bryan	ACDF with allograft and Orion System	41	42	47	47.7	21/20	23/19	0	2
Sasso et al. [38]	Bryan	ACDF with allograft and plate	242	221	44	44.7	110/132	113/108	61	83
Delamarter et al. [9]	ProDisc-C	ACDF with allograft and angle plate	103	106	42	43.5	46/57	49/57	38	57
Burkus et al. [3]	Prestige ST	ACDF with allograft and Atlantis System	276	265	43	43.9	128/148	122/143	132	138

CDA = cervical disc arthroplasty; ACDF = anterior cervical discectomy and fusion; PCM = porous-coated motion; NR = not reported; IDE = investigational device exemption.