Which questions matter with platelet-rich plasma (PRP)?

Sources

1. Blood from seven donors was processed through five commercial PRP systems (Arthrex Angel, Emcyte Genesis CS, Arteriocyte Magellan, Harvest SmartPrep, Biomet GPS III). White-cell concentration ranged from 11.0 to 27.3 thousand/uL between systems, neutrophil concentration from 0.6 to 9.4 thousand/uL, red-cell concentration from under 1.1 to 3.2 million/uL, and pH from 6.95 to over 7.26. The authors advise caution in interpreting clinical PRP results because the product itself differs by device.

   Degen RM, et al. — Commercial Separation Systems Designed for Preparation of Platelet-Rich Plasma Yield Differences in Cellular Composition.. HSS Journal, 2017. DOI: 10.1007/s11420-016-9519-3.

2. A single-donor comparison of five PRP preparations (RegenPRP, Mini GPS III, Selphyl, Arthrex ACP and a laboratory protocol) across ten donors found two systems produced leukocyte-RICH PRP with higher red-cell, white-cell and neutrophil proportions while three produced leukocyte-poor PRP, and that platelet and growth-factor doses varied substantially between devices, with platelet dose positively correlated with every growth factor measured.

   Magalon J, et al. — Characterization and comparison of 5 platelet-rich plasma preparations in a single-donor model.. Arthroscopy, 2014. DOI: 10.1016/j.arthro.2014.02.020.

3. RESTORE, the largest and most rigorously blinded placebo-controlled PRP trial in knee OA (n=288, participant-, injector- and assessor-blinded), gave three weekly injections of a commercial leukocyte-poor PRP or saline. At 12 months the change in knee pain was -2.1 vs -1.8 points (difference -0.4; 95% CI -0.9 to 0.2; P=.17) and the change in medial tibial cartilage volume was -1.4% vs -1.2% (difference -0.2%; P=.81). Twenty-nine of 31 prespecified secondary outcomes showed no between-group difference. The authors concluded the findings do not support the use of PRP for knee OA.

   Bennell KL, et al. — Effect of Intra-articular Platelet-Rich Plasma vs Placebo Injection on Pain and Medial Tibial Cartilage Volume in Patients With Knee Osteoarthritis: The RESTORE Randomized Clinical Trial.. JAMA, 2021. DOI: 10.1001/jama.2021.19415.

4. A Bayesian network meta-analysis of 48 Level I-II randomized trials (9,338 knees) with a minimum 6-month follow-up ranked the four commonest intra-articular injections. HA and PRP both significantly improved pain versus placebo; HA, PRP and BMAC all significantly improved function versus placebo. SUCRA rankings were PRP 91.54, BMAC 76.46, HA 53.12, corticosteroid 15.18 and placebo 13.70 - corticosteroid ranked barely above placebo at six months and beyond.

   Jawanda H, et al. — Platelet-Rich Plasma, Bone Marrow Aspirate Concentrate, and Hyaluronic Acid Injections Outperform Corticosteroids in Pain and Function Scores at a Minimum of 6 Months as Intra-Articular Injections for Knee Osteoarthritis: A Systematic Review and Network Meta-analysis.. Arthroscopy, 2024. DOI: 10.1016/j.arthro.2024.01.037.

5. FDA states verbatim of stem cell products, stromal vascular fraction (adipose-derived cells), umbilical cord blood, Wharton's jelly, amniotic fluid and exosome products: 'None of these products have been approved for the treatment of any orthopedic condition, such as osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain, or shoulder pain.' The only FDA-approved stem cell products in the United States are blood-forming (hematopoietic progenitor) cells derived from umbilical cord blood, approved only for disorders of blood production, and there are currently NO FDA-approved exosome products.

   U.S. Food and Drug Administration — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. FDA (Center for Biologics Evaluation and Research), 2020.