What to ask about blood-based PRP and a sore joint

What to do when an answer isn't clear

Ask the clinician to name the joint problem in plain words. Then ask why the suggested care suits your exam.

Ask what could happen if you wait. Don't let anyone rush you into deciding that day.

Write your main questions before the visit. The note works like a bookmark when the talk moves quickly.

Bring someone you trust if that helps. You'll both hear the same answers and next steps.

Sources

1. 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.

2. 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.

3. A 12-centre randomized controlled trial of 230 patients with chronic lateral epicondylar tendinopathy compared tendon needling with leukocyte-enriched PRP against tendon needling alone. At 12 weeks there was no significant difference (55.1% versus 47.4% pain improvement; P=.163). At 24 weeks the PRP group reported 71.5% versus 56.1% pain improvement (P=.019), a 83.9% versus 68.3% success rate (P=.037), and significantly less residual elbow tenderness (29.1% versus 54.0%; P=.009). No significant complications occurred in either group.

   Mishra AK, Skrepnik NV, Edwards SG, et al. — Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients. American Journal of Sports Medicine, 2014. DOI: 10.1177/0363546513494359.

4. A placebo-controlled, double-blind randomized trial of 40 patients with chronic rotator cuff tendinopathy compared a single ultrasound-guided subacromial injection of 5 mL PRP with 5 mL saline, with both groups completing a 6-week standard exercise programme and follow-up to one year. PRP did not produce better outcomes than saline on any measure - a reminder that the exercise programme, not the injectate, carried the improvement.

   Kesikburun S, Tan AK, Yilmaz B, et al. — Platelet-rich plasma injections in the treatment of chronic rotator cuff tendinopathy: a randomized controlled trial with 1-year follow-up. American Journal of Sports Medicine, 2013. DOI: 10.1177/0363546513496542.

5. 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.

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.