Table 1. Criteria for selecting studies.

In this review, we have considered studies investigating the effects of Platelet-Rich Plasma treatment on patients with knee osteoarthritis. Our inclusion criteria were limited to studies published in English and those that met the specifications outlined in this table.

Inclusion Criteria	Exclusion Criteria
Randomized clinical trials	Observational clinical studies
Placebo-controlled clinical trials	Cross-sectional clinical studies
Single-blinded clinical trials	Retrospective clinical studies
Double-blinded clinical trials	Case Reports
Non-blinded clinical trials	Systematic reviews
Pilot clinical studies	Meta analyses
	Narrative reviews
	Commentaries/opinions
	Preclinical studies