A Higher Platelet Dose May Yield Better Clinical Outcomes for PRP in the Treatment of Knee Osteoarthritis: A Systematic Review

Abstract

PurposeTo determine if the platelet dose administered during a platelet-rich plasma (PRP) injection for knee osteoarthritis (OA) impacts clinical outcomes. MethodsA systematic review was performed by searching PubMed, Cochrane Library, and Embase for randomized controlled trials with at least one study arm using PRP for knee OA. Only studies that provided a platelet count, concentration, or dose with a minimum of 6-month outcome scores were included. Studies in which the PRP group had statistically significant positive outcomes were separated from those without statistical significance. The average platelet doses for studies with positive outcomes in the PRP group were compared to those without positive outcomes. ResultsAfter exclusion criteria were applied, 29 studies were analyzed. Of the 29, there were 31 arms that used PRP as a treatment method of which 28 had statistically significant positive outcomes at 6 months compared to the control group. The mean platelet dose in the 28 with a positive outcome was 5500 ± 474 x106, whereas the 3 that had no positive difference had a mean platelet dose of 2302 ± 437 x106 (p < 0.01). There were 18 studies with 12-month outcomes with 16/18 having positive outcomes. The positive studies had an average platelet dose of 5464 ± 511, whereas the studies that had no statistical difference had an average platelet dose of 2253 ± 753 x106 (p < 0.05). ConclusionsImproved clinical outcomes from PRP injections for knee OA may be related to a higher platelet dose. Level of EvidenceLevel II, systematic review of Level I and II studies