What to know before choosing PRP

Sources

1. The 2019 ACR/Arthritis Foundation osteoarthritis guideline makes STRONG recommendations for exercise, weight loss in people with overweight or obesity, self-management programmes, tai chi, cane use, tibiofemoral bracing, topical and oral NSAIDs and intra-articular glucocorticoid injections for knee OA. Its conditional recommendations cover balance exercises, yoga, CBT, acupuncture, thermal modalities, radiofrequency ablation, acetaminophen, duloxetine and tramadol. Anything offered before a course of the strongly recommended options is being offered out of order.

   Kolasinski SL, Neogi T, Hochberg MC, et al. — 2019 American College of Rheumatology/Arthritis Foundation Guideline for the Management of Osteoarthritis of the Hand, Hip, and Knee. Arthritis & Rheumatology, 2020. DOI: 10.1002/art.41142.

2. The OARSI non-surgical management guideline places intra-articular corticosteroids, intra-articular hyaluronic acid and aquatic exercise at Level 1B/Level 2 for KNEE osteoarthritis depending on comorbidity status, and specifically does NOT recommend them for hip or polyarticular osteoarthritis. Oral and transdermal opioids are strongly not recommended and acetaminophen is conditionally not recommended.

   Bannuru RR, Osani MC, Vaysbrot EE, et al. — OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthritis and Cartilage, 2019. DOI: 10.1016/j.joca.2019.06.011.

3. The ESSKA-ICRS consensus applied the RAND/UCLA appropriateness method to 216 clinical scenarios for intra-articular PRP in knee OA. Only 84 scenarios (38.9%) were rated appropriate, 9 (4.2%) inappropriate and 123 (56.9%) uncertain. PRP was judged appropriate in patients aged 80 or under with KL grade 0-III osteoarthritis AFTER failed conservative non-injective or injective treatment; it was NOT considered appropriate as a first treatment, nor in KL grade IV (bone-on-bone) osteoarthritis, where 91.7% and 87.5% of scenarios respectively were uncertain.

   Kon E, de Girolamo L, Laver L, et al. — Platelet-rich plasma injections for the management of knee osteoarthritis: The ESSKA-ICRS consensus. Recommendations using the RAND/UCLA appropriateness method for different clinical scenarios. Knee Surgery, Sports Traumatology, Arthroscopy, 2024. DOI: 10.1002/ksa.12320.

4. In the RESTORE trial - the largest placebo-controlled PRP trial in knee osteoarthritis - 288 adults aged 50+ with symptomatic Kellgren-Lawrence grade 2-3 medial knee OA received three weekly intra-articular injections of leukocyte-poor PRP from a commercial system or saline placebo. At 12 months the mean change in knee pain was -2.1 points with PRP versus -1.8 with saline (difference -0.4; 95% CI -0.9 to 0.2; P=.17) against a minimum clinically important difference of 1.8, and the change in medial tibial cartilage volume was -1.4% versus -1.2% (difference -0.2%; 95% CI -1.9% to 1.5%; P=.81). Twenty-nine of 31 prespecified secondary outcomes showed no significant between-group difference. The authors concluded the findings do not support use of PRP for knee OA.

   Bennell KL, Paterson KL, Metcalf BR, 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.

5. A meta-analysis of 18 Level I randomized trials (811 patients receiving PRP, 797 receiving hyaluronic acid, mean follow-up 11.1 months) found mean improvement in total WOMAC scores was significantly higher with PRP (44.7%) than with hyaluronic acid (12.6%) (P<.01), and 6 of 11 VAS-reporting studies found significantly less pain with PRP at latest follow-up.

   Belk JW, Kraeutler MJ, Houck DA, et al. — Platelet-Rich Plasma Versus Hyaluronic Acid for Knee Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials. American Journal of Sports Medicine, 2021. DOI: 10.1177/0363546520909397.

6. A systematic review of 105 clinical PRP studies in orthopaedics published 2006-2016 found that only 11 (10%) described the preparation protocol clearly enough for another investigator to repeat it, and only 17 (16%) reported any quantitative metric of the final PRP composition. The authors concluded that the current reporting of PRP preparation and composition does not allow the PRP products actually delivered to patients to be compared between studies.

   Chahla J, Cinque ME, Piuzzi NS, et al. — A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature. Journal of Bone and Joint Surgery (American), 2017. DOI: 10.2106/JBJS.16.01374.

7. Medicare's national coverage policy covers autologous platelet-rich plasma ONLY for patients with chronic non-healing diabetic, pressure and/or venous wounds, and only within an approved coverage-with-evidence-development clinical study. There is no Medicare national coverage for PRP in osteoarthritis or tendinopathy, which is why these injections are billed to the patient as cash-pay.

   Centers for Medicare & Medicaid Services — Autologous Platelet-rich Plasma (Coverage with Evidence Development). CMS.gov, 2024.

8. The devices used to spin PRP at the point of care are cleared by FDA as clinical centrifuges, product code JQC, a Class I device under 21 CFR 862.2050 - for example the Biomet GPS Platelet Separation Kit (K030555, cleared 2003) and the Harvest SmartPrep2 / SmartPrep Platelet Concentration System (K103340, cleared 2010). That clearance covers the equipment that separates blood. It is not an FDA approval of platelet-rich plasma as a treatment for osteoarthritis, tendinopathy or any other orthopedic condition, and copy must never blur the two.

   U.S. Food and Drug Administration (Center for Devices and Radiological Health) — 510(k) Premarket Notification database and Product Classification: JQC, Centrifuges (Micro, Ultra, Refrigerated) For Clinical Use, 21 CFR 862.2050. FDA accessdata (CDRH device databases), 2003.

9. A Bayesian network meta-analysis restricted to LARGE randomized trials (at least 100 patients per group; 57 trials, 22,795 participants, 18 intra-articular interventions) found treatment effects were larger in the 35 high-risk-of-bias trials than in the 22 low/unclear-risk trials. Excluding high-risk trials, the effects of 16 of the 18 intra-articular interventions in knee or hip OA were smaller than the minimal clinically important difference and most were consistent with placebo effects; triamcinolone had the highest probability of exceeding the MID at weeks 2-6.

   Pereira TV, Saadat P, Bobos P, et al. — Effectiveness and safety of intra-articular interventions for knee and hip osteoarthritis based on large randomized trials: A systematic review and network meta-analysis. Osteoarthritis and Cartilage, 2025. DOI: 10.1016/j.joca.2024.08.014.

10. A meta-analysis of 73 articles covering 5,895 patients quantified the PLACEBO response to intra-articular injection in knee osteoarthritis: statistically and clinically significant improvements in pain, function and quality of life at 1, 3 and 6 months, with responder rates above 50% at each of those points, declining by 12 months. The placebo response was stronger in trials with more female participants and in more recently published trials. This is why an uncontrolled 'our patients improved' figure carries almost no information.

    Previtali D, Boffa A, Di Laura Frattura G, et al. — Placebo response to intra-articular injections in knee osteoarthritis: magnitude, evolution over time, and influencing factors. A systematic review and meta-analysis with meta-regression. EFORT Open Reviews, 2025. DOI: 10.1530/EOR-2025-0022.