Table 2.

The technique used

	Elksniņš-Finogejevs et al.23	Forogh et al.17	Uslu Güvendi et al.18	Huang et al.24	Jubert et al.19
Frequency of injections	Single	Single	Single PRP: one PRP injection; three PRP: three PRP injections with 1-week interval	PRP group: (3 times, 4 ml, every 3 weeks); CS group: single	Single
Use of ultrasound guidance for verification of injection	Yes	No	No	No	No
Agent injected
PRP	8 ml of PRP	5 ml of PRP was activated by adding 0.5 ml of a calcium gluconate solution (1 g/10 ml); PRP platelet count was 1501×10³	Venous blood (18 ml) + 2 ml citrate dextrose was separated as plasma	IA-PRP (3 times, 4 ml, every 3 weeks)	4 ml autologous PRP, a median value of 0.99×106 platelets/ml
CS	Triamcinolone acetonide (Kenalog) (1 ml of 40 mg/ml) plus lidocaine (5 ml of 2%) in a single syringe	1 ml of Depo-Medrol (containing 40 mg of methylprednisolone acetate)	1 ml suspension containing 6.43 mg of betamethasone dipropionate (equivalent to 5.0 mg of betamethasone) and 2.63 mg of betamethasone sodium phosphate (equivalent to 2.0 mg betamethasone).	IA-CS (1 ml)	2 ml betamethasone: 6 mg betamethasone sodium phosphate and betamethasone acetate 6 mg (Merck) and 2 ml bupivacaine 0.25% (B. Braun)
	Naderi Nabi et al.20	Freire et al.21	Khan et al.25	Nunes-Tamashiro et al.22
Frequency of injections	Once a month, for 3 consecutive months	Single	Twice, the second injection was given after 2 months	Single
Use of ultrasound guidance for verification of injection	Yes	No	No	No
Agent injected
PRP	5 ml of PRP	5 ml of PRP	5 ml of PRP	Platelet value of 2.5–5 times the number of platelets in 45–50 ml of collected blood
CS	40 mg triamcinolone	2.5 ml of triamcinolone acetate	1 ml (40 mg) of triamcinolone acetonide and 4 ml of 1% lidocaine hydrochloride mix	40 mg (2 ml) of triamcinolone hexacetonide

CS, corticosteroid; IA, intra-articular; PRP, platelet-rich plasma.