Does PRP work? What do the results really say?

What have we learned about sore knees?

Knee research points both ways, so a plain yes or no isn't honest. Some studies found less soreness, while a large study didn't find a clear difference between PRP and a salt water shot.

Age alone can't decide whether the treatment fits. Your exam, X-ray, amount of joint damage, daily limits, and past care matter more.

Does a good tendon result apply everywhere?

It doesn't. Some studies of elbow and foot tendons found help, but other tendon studies didn't find the same benefit.

Shoulder findings are mixed, and an elbow result can't answer for your shoulder. Ask whether the study tested your tendon and a similarly prepared blood shot.

What do we know about sore hips?

Hip research is smaller and less clear than knee research. Some people improved, but PRP hasn't shown a sure, lasting benefit over other choices.

Hip soreness can come from the back or nearby muscles too. That's why an exam comes before deciding whether any shot belongs near your hip.

What answer should you expect at a clinic?

A QC Kinetix consultation may cover regenerative treatments, meaning non-surgical care that can include this blood-based shot after your joint and health are checked. No result is promised.

What matters now is whether the study matches your joint and diagnosis. If the answer isn't clear, ask which body part was studied and how the blood shot was prepared.

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. The AAOS third-edition clinical practice guideline for non-arthroplasty management of knee osteoarthritis contains 29 recommendations, and the work group explicitly identified intra-articular corticosteroid, hyaluronic acid AND platelet-rich plasma as areas needing better research - including osteoarthritis characterisation, severity stratification, clinically relevant outcomes with controls for bias, and cost-effectiveness analysis. PRP is presented as an open research question in this guideline, not as a settled treatment.

   Brophy RH, Fillingham YA — AAOS Clinical Practice Guideline Summary: Management of Osteoarthritis of the Knee (Nonarthroplasty), Third Edition. Journal of the American Academy of Orthopaedic Surgeons, 2022. DOI: 10.5435/JAAOS-D-21-01233.

4. The American Academy of Physical Medicine and Rehabilitation convened a technical expert panel that ran a structured literature review (2023, updated through June 2025) and a modified Delphi process, and issued five evidence-based clinical recommendations plus 11 consensus-based best practices for PRP in knee osteoarthritis. The statement is explicit that orthobiologic therapies 'remain an evolving area of practice' and that robust, dose-dependent randomized controlled trials are still needed to establish PRP's clinical effects.

   Borg-Stein J, Jayaram P, Colorado BS, et al. — AAPM&R guidance statement on platelet rich plasma for knee osteoarthritis. PM&R, 2026. DOI: 10.1002/pmrj.70144.

5. A systematic review of 26 studies of PRP for lateral epicondylitis assessed against minimal clinically important difference thresholds rather than statistical significance found the mean improvement exceeded the MCID from week 4 through week 104 for VAS and DASH, and from weeks 4-52 for the Mayo score. Both leukocyte-rich and leukocyte-poor systems met the MCID at almost every observation point.

   Niemiec P, Szyluk K, Jarosz A, et al. — Effectiveness of Platelet-Rich Plasma for Lateral Epicondylitis: A Systematic Review and Meta-analysis Based on Achievement of Minimal Clinically Important Difference. Orthopaedic Journal of Sports Medicine, 2022. DOI: 10.1177/23259671221086920.

6. A systematic review and meta-analysis of PRP for hip osteoarthritis found intra-articular PRP more effective at time points earlier than three months, with diverse results between 4 and 12 months and only one included study reporting significantly better outcomes for PRP than the comparator. The authors judged PRP possibly beneficial and safe at mid-term follow-up but said its superiority over alternatives such as hyaluronic acid remains unclear.

   Medina-Porqueres I, Ortega-Castillo M, Muriel-Garcia A — Effectiveness of platelet-rich plasma in the management of hip osteoarthritis: a systematic review and meta-analysis. Clinical Rheumatology, 2021. DOI: 10.1007/s10067-020-05241-x.

7. 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.