Table 1.

Characteristics of the included studies.

Reference	Design	Sample size	Follow-up (months)
Adhikari et al. (14)	Retrospective	158	–
Byvaltsev et al. (15)	Retrospective	214	–
Delgado-López et al. (16)	Retrospective	300	–
Devin et al. (17)	Retrospective	2056	1
Dewan et al. (18)	Retrospective	565	3
Emohare et al. (19)	Retrospective	303	–
Garg et al. (20)	Retrospective	538	3
Gun-Ill et al. (21)	Retrospective	571	3
Haimoto et al. (22)	Retrospective	515	6
Heller et al. (23)	Retrospective	683	3
Hill et al. (24)	Retrospective	300	1
Li et al. (25)	Retrospective	569	12
Liu et al. (26)	Retrospective	334	–
Maajid et al. (27)	Retrospective	303	3
Martin et al. (28)	Retrospective	306	1
Martin et al. (29)	Retrospective	289	1
Oktay et al. (30)	Retrospective	209	3
Pahys et al. (31)	Retrospective	518	–
Strom et al. (33) (cervical)	Retrospective	171	12
Strom et al. (32)	Retrospective	253	12
Sweet et al. (34)	Retrospective	1732	12
Takeuchi et al. (35)	Retrospective	668	3