592 - Effect of Platelet Concentration in PRP on Patient Reported Pain Outcomes: A Systematic Review and Meta-Analysis

Objectives: The purpose of this study is to identify a dose dependency effect of platelet concentration in knee osteoarthritis as assessed by validated patient pain reported outcomes.

Design: Systematic Review and Meta-analysis

Results: Of the 4,228 studies identified from the search, 17 trials examining HA and PRP were included in the analysis. The majority of studies used VAS (n=15) to assess pain. Other included outcome scales included WOMAC Pain subscale (n=9), and KOOS Pain subscale (n=2). Pooled analysis found a significant improvement in pain scores for those treated with PRP when compared to HA (SMD = .84; 95% CI .48 to 1.19, P< .01). We observed high level of heterogeneity, shown by a I2 statistic for this outcome of 93.95%. Our study found a significant difference between PRP groups (P< .05). The low concentration group resulted in a large effect size (SMD = 1.30; 95% CI .63 to 1.98, P1< .01). Both the moderate and high concentration groups resulted in moderate effect sizes respectively (SMD = .42; 95% CI .00 to 0.84, P=.01; SMD = .55; 95% CI -0.08 to 1.18, P< .01).

Conclusions: Overall, our analysis found only the ‘low’ concentration group resulted in a significant large effect size, while compared to moderate and high concentrations of platelets. This is the first study to primarily analyze the effects of platelet concentrations in PRP on patient reported outcomes. There are currently very few studies that examine effect of platelet concentration in PRP-on-PRP effectiveness. However, given methodological limitations of included RCTs, it is clear that to this day, there remains questions about how the treatment should be prepared (i.e. optimal leukocyte and platelet concentration, activation vs. no activation, number and length of spins). Thus, further research is needed.