Table 1.

General characteristics of the included literature.

Study	Year	Country	Study design	Subjects, n		Population	Primary diagnosis	Operative location	Irrigation techniques and Volumes
				E	C				E	C
Cheng et al. (27)	2005	China	RCT	208	206	Adult	Varied	Varied	0.35% P-I, 2L	Normal saline, 2L
Chang et al. (28)	2006	China	RCT	120	124	Adult	LIS	LS	0.35% P-I , 2LC:	Normal saline, 2L
Tomov et al. (29)	2015	USA	RCS	1173	1252	Adult	Varied	Varied	0.3% P-I , N/A	N/A
van Herwijnen et al. (30)	2016	UK	RCS	71	15	Pediatric	Scoliosis	Varied	1% P-I , 6L	Saline with 80 mg gentamicin, 7L
De Luna et al. (31)	2017	Italy	RCT	25	25	Adult	Scoliosis	Varied	3% P-I , 2L	Normal saline, 2L
Fei et al. (32)	2017	China	RCT	40	40	Adult	PLID	Lumbar	0.1% P-I , 0.2L	Normal saline, N/A
Yamada et al. (33)	2018	Japan	RCS	301	741	Adult	N/A	Varied	0.38% P-I , 0.52L	Normal saline, N/A
Onishi et al. (34)	2019	Japan	RCS	177	146	Adult	N/A	Varied	1% P-I , N/A	Normal saline, N/A
Lemans et al. (35)	2019	Netherlands	RCS	217	257	Adult	N/A	Varied	500mL P-I solution; concentration: 1.3g/L	Normal saline, N/A
Sigari et al. (36)	2020	Germany	RCT	468	468	Adult	Scoliosis, DD	Varied	3% P-I , N/A	Normal saline, N/A
Carballo Cuello et al. (37)	2021	USA	RCS	144	134	Adult	Varied	Lumbar	0.35% P-I , 1L	Normal saline, 1L
Roberto et al. (38)	2021	USA	RCS	13	88	Pediatric	Spinal deformity	Varied	3.5% w/v P-I , N/A	No irrigation techniques
Lin et al. (39)	2022	China	RCS	120	124	Adult	Varied	Lumbar	0.35% P-I , 1L	Normal saline, N/A
Inojie et al. (40)	2023	Nigeria	RCT	40	40	Adult	N/A	Varied	0.35% P-I , 1L	1L saline with 80 mg gentamicin

C, Controlled group; DD, degenerative diseases; E, Experimental group; LIS, lumbar instability; LS, lumbosacral; PLID, prolapsed lumbar intervertebral discs; P-I, povidone-iodine; RCS, Retrospective cohort study; RCT, randomized controlled trial.