Platelet-Rich Plasma (PRP) Therapy for Knee and Shoulder Pain

Platelet-rich plasma (PRP) is an injection made from a concentrate of your own blood, used for joint and tendon pain in the knee and shoulder. How well it works depends heavily on the condition. For some problems the trials are encouraging, and for others PRP has done no better than a saline injection.

Understanding PRP Therapy

PRP therapy involves drawing a small sample of your blood, processing it in a centrifuge to concentrate the platelets and their growth factors, and then injecting this concentrated preparation directly into the affected area under ultrasound guidance. Platelets contain growth factors and other signaling proteins involved in tissue repair, which PRP delivers to the injured area in concentrated form.

PRP for Knee Pain

For knee pain from osteoarthritis, the evidence conflicts. Meta-analyses of randomized trials favor PRP over hyaluronic acid and saline on some measures at 6 to 12 months, but the quality of that evidence is low (Filardo 2021, Belk 2021). The RESTORE trial found no difference between PRP and saline in knee pain or cartilage volume at 12 months (Bennell 2021). The 2019 American College of Rheumatology/Arthritis Foundation and OARSI guidelines both recommend against PRP for knee osteoarthritis (Kolasinski 2020, Bannuru 2019), while the 2021 American Academy of Orthopaedic Surgeons guideline says it may reduce pain and improve function, with a Limited strength rating. Claims that PRP rebuilds cartilage or slows arthritis are not supported. In RESTORE, cartilage volume declined by the same amount with PRP and saline.

For degenerative meniscal tears managed without surgery, a 2024 systematic review found encouraging results but noted a lack of high-quality studies (Elphingstone 2024). Patellar tendinopathy (jumper’s knee) is mixed: one small trial found faster recovery at 12 weeks with no difference by 26 weeks (Dragoo 2014), and a three-arm trial found PRP no better than saline (Scott 2019).

PRP for Shoulder Pain

The shoulder evidence is weaker than the marketing. In a placebo-controlled trial of chronic rotator cuff tendinopathy, an ultrasound-guided PRP injection added to an exercise program did no better than saline at any point through one year (Kesikburun 2013), and a 2018 review found the evidence insufficient to recommend PRP routinely for rotator cuff tendinopathy (Le 2018). Shoulder osteoarthritis and subacromial bursitis have even less trial data.

Who Is a Good Candidate for PRP?

PRP is most often considered for chronic tendon problems that have not improved with an exercise program, and for mild to moderate knee osteoarthritis after an honest discussion of the conflicting evidence above. Realistic expectations about results and timeline matter. PRP may be less effective for severe, advanced joint degeneration where significant structural damage has already occurred.

What to Expect

The visit typically takes 45 to 60 minutes. After a blood draw, the sample is processed for about 10 to 15 minutes before the injection. Soreness at the injection site for a few days is common. Avoid anti-inflammatories such as ibuprofen and naproxen for 2 weeks before and 2 weeks after the injection. In trials that found a benefit, the difference from the comparison treatment usually appeared at three to six months rather than in the first weeks. A single injection is the usual protocol for tendon problems (Fitzpatrick 2017), while knee osteoarthritis trials have used one to three (Patel 2013, Bennell 2021). Instructions for the days and weeks afterward are in the PRP aftercare instructions.

Why Choose Modal Pain for PRP

Dr. Movshis is board-certified in anesthesiology and pain medicine and performs PRP injections under ultrasound guidance to confirm placement in the targeted tissue. We evaluate each patient individually to determine whether PRP is the most appropriate treatment for their specific condition.

References

This article is reviewed against the peer-reviewed literature. Citations retrieved from PubMed.

1. Filardo G, Previtali D, Napoli F, Candrian C, Zaffagnini S, Grassi A. PRP Injections for the Treatment of Knee Osteoarthritis: A Meta-Analysis of Randomized Controlled Trials. Cartilage. 2021. doi:10.1177/1947603520931170 · PubMed
2. Belk JW, Kraeutler MJ, Houck DA, Goodrich JA, Dragoo JL, McCarty EC. Platelet-Rich Plasma Versus Hyaluronic Acid for Knee Osteoarthritis: A Systematic Review and Meta-analysis of Randomized Controlled Trials. The American Journal of Sports Medicine. 2021. doi:10.1177/0363546520909397 · PubMed
3. 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 · PubMed
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7. 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. The Journal of Bone and Joint Surgery. American Volume. 2017. doi:10.2106/JBJS.16.01374 · PubMed
8. 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 · PubMed
9. 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 · PubMed
10. Dragoo JL, Wasterlain AS, Braun HJ, Nead KT. Platelet-rich plasma as a treatment for patellar tendinopathy: a double-blind, randomized controlled trial. The American Journal of Sports Medicine. 2014. doi:10.1177/0363546513518416 · PubMed
11. Scott A, LaPrade RF, Harmon KG, et al. Platelet-Rich Plasma for Patellar Tendinopathy: A Randomized Controlled Trial of Leukocyte-Rich PRP or Leukocyte-Poor PRP Versus Saline. The American Journal of Sports Medicine. 2019. doi:10.1177/0363546519837954 · PubMed
12. Le ADK, Enweze L, DeBaun MR, Dragoo JL. Current Clinical Recommendations for Use of Platelet-Rich Plasma. Current Reviews in Musculoskeletal Medicine. 2018. doi:10.1007/s12178-018-9527-7 · PubMed
13. Elphingstone JW, Alston ET, Colorado BS. Platelet-rich plasma for nonoperative management of degenerative meniscal tears: A systematic review. Journal of Orthopaedics. 2024. doi:10.1016/j.jor.2024.03.009 · PubMed