Table 3.

Level I primary studies on platelet-rich plasma for knee and hip osteoarthritis over the past 5 years. *Not a comprehensive list. N refers to the total number of knees/hips that underwent treatment in each study. BMAC, bone marrow aspirate concentrate; HA, hyaluronic acid; HHS, Harris Hip Score; IKDC, International Knee Documentation Committee; LOE, level of evidence; KOOS, Knee Injury and Osteoarthritis Outcome Score; n.s., not significant; PRP, platelet-rich plasma; VAS, visual analog scale; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index

Knee Studies	LOE	N	Outcomes Reported	Outcomes
Huang et al., 2019 [22]	I	40 PRP, 40 HA	WOMAC	PRP group significantly improved compared to HA group
			VAS	No significant difference between groups
Raeissadat et al., 2021 [23]	I	52 PRP, 49 HA	WOMAC	PRP group significantly improved compared to HA group
			VAS	PRP group significantly improved compared to HA group
Sdeek et al., 2021 [24]	I	95 PRP, 94 HA	WOMAC, VAS, IKDC	No significant difference between groups for WOMAC, VAS, IKDC
Dulic et al., 2021 [25]	I	34 PRP, 111 BMAC, 30 HA	WOMAC	Both PRP and BMAC groups significantly improved compared to HA, but no difference between BMAC and PRP groups
			IKDC	BMAC significantly improved compared to HA, but no significant difference between PRP and HA
			KOOS	No significant differences between groups
Di Martino et al., 2019 [26]	I	85 PRP, 82 HA	VAS, IKDC	No significant differences between groups for VAS or IKDC
Hip Studies	LOE	N	Outcomes Reported	Outcomes
Kraeutler et al., 2021 [11]	I	18 PRP, 13 HA	WOMAC	No significant differences between groups
Villanova-López et al., 2020 [27]	I	38 PRP, 36 HA	WOMAC, VAS, HHS	No significant differences between groups for WOMAC or VAS. PRP group reported significantly better HHS compared with HA group