Related Experiment Video
Updated: Nov 18, 2025
Preparation, Procedures and Evaluation of Platelet-Rich Plasma Injection in the Treatment of Knee Osteoarthritis
Published on: January 4, 2019
A retrospective analysis of a commercially available platelet-rich plasma kit during clinical use
Meredith H Prysak1, Christopher P Kyriakides2, Tyler A Zukofsky1
1Orthobond Corporation, Princeton, New Jersey, USA.
Introduction:
Point-of-care analyses of platelet-rich plasma (PRP) are not routine in the orthopedic regenerative medicine field. Therefore, many physicians rely on the manufacturer's reported content for commercial preparation kits. This contributes to a knowledge gap between injectate content and patient outcome.
Objective:
To assess whether the EmCyte PurePRP II 60-mL preparation kit returns PRP content that meets the manufacturer's expectations when used during routine clinical care for a heterogenous patient population, and to determine whether a change in PRP yield volume affects injectate content. Protocol A (exclusion of granulocytes and low hematocrit) and Protocol B (inclusion of granulocytes and higher hematocrit) were evaluated.
Design:
Retrospective review.
Setting:
Private practice.
Participants:
One hundred five patients (118 preparations) treated for orthopedic conditions over an 8-month period via PRP injection. Thirteen patients had two independently made preparations on different treatment days that qualified for analysis.
Interventions:
Not applicable.
Main Outcome Measures:
Complete blood count (absolute counts and calculated fold enrichment from baseline of platelets, white blood cells, red blood cells, granulocytes, lymphocytes, monocytes; and hematocrit levels). Confounding variables included age, gender, and preparation yield volume.
Results:
During routine clinical use, the cellular content of both Protocols A and B met or exceeded the manufacturer's expectations of platelet enrichment and granulocyte inclusion or exclusion. Hematocrit values were slightly higher than anticipated from Protocol A preparations. The modification of yield volume from 7 to 4 mL led to a significant difference in platelet enrichment without affecting absolute cell counts (2.88; 95% confidence interval [CI] 1, 4.76; P = .003). Both gender and age moderately affected the level of platelet enrichment from baseline but did not significantly affect absolute platelet counts.
Conclusion:
In the absence of widespread characterization, confirming the variation in commercial PRP kits during clinical use is crucial.
