Ten randomized controlled trials were included in this meta-analysis that compared pain and functional outcomes between intraarticular platelet-rich plasma injection (PRP) and either intraarticular hyaluronic acid (HA) injections or saline injections in knee osteoarthritis treatment. Outcomes were assessed at 6 and 12 months postinjection. In comparison to HA injections, PRP injections demonstrated similar pain and functional outcomes at 6 months postinjection, and significantly better pain and functional outcomes at 12 months postinjection. The effect sizes compared to HA for pain and function at 12 months exceeded the MCID, however, these findings should be interpreted with caution as only a few studies could be pooled for these outcomes. Results from one study that compared PRP injections to saline demonstrated significantly lower scores for WOMAC pain and function, these differences exceeded the MCID at 6 and 12 months.