Table 2.

Therapeutic parameters of included RCTs.

Study(year)	Injection site	Injection volume (ml)	LP-PRP or LR-PRP	Number of injections	Injection time
Dório et al. (29)	IA	1.4 ~ 5 ml	LP	2	Once every 2 weeks, 4 weeks
Bennell et al. (27)	IA	5 ml	LP	3	Once a week, 3 weeks
Görmeli et al. (45)	IA	5 ml	-	3	Once a week, 3 weeks
Wu et al. (16)	IA	4 ml	LR	1	-
Lin et al. (31)	IA	2 ml	LP	3	Three times a week, 1 week
Elik et al. (32)	IA	4 ml	-	3	Once a week, 3 weeks
Barman et al. (33)	IO + IA	10 ml + 8 ml	-	1	-
	IA	8 ml	-	-
Nunes et al. (35)	IA	-	-	1	-
Patel et al. (30)	IA	8 ml	LP	2	Once every three weeks, 6 weeks
Bastos et al. (37)	IA	-	-	1	-
Raeissadat et al. (41)	IA	-	LR	2	Once a month, 2 months
Ghai et al. (42)	IA	8 ml	-	1	-
Rayegani et al. (39)	IA	4 ~ 6 ml	LR	2	Once a month, 2 months
Bastos et al. (37)	IA	-	LP	1	-
Su et al. (34)	IO + IA	2 ml + 2 ml	LR	2	Once every 2 weeks, 4 weeks
	IA	6 ml	-	-
Nouri et al. (26)	IA	5 ml	-	2	Once every 2 weeks, 4 weeks
Cömert Kiliç et al. (28)	IA	-	-	5	Five times a month, 1 month
Fernández et al. (40)	IA	5 ml	LP	1	-
Asadpour et al. (44)	IA	1 ml	-	1	-
Di Sante et al. (49)	IA	3 ml	-	3	Once a week, 3 weeks
Görmeli et al. (43)	IA	-	-	1	-
Guney et al. (46)	IA	4 ml	-	1	-
Malahias et al. (47)	IA	2 ml	-	2	Once every 2 weeks, 4 weeks
Mei-Dan et al. (48)	IA	2 ml	-	3	Once every 2 weeks, 4 weeks

IA, intra-articular; IO, intra-osseous; LR-PRP, Leukocyte-Rich Platelet-Rich Plasma; LP-PRP, Leukocyte-Poor Platelet-Rich Plasma; “-”, not report.