Single vs Multiple Injections of Platelet-Rich Plasma (PRP) - What Works Best For Knee OA?

Knee osteoarthritis (OA) is a significant degenerative joint disease that impacts the quality of life and daily functions of those impacted [1]. Treatment options range from non-surgical interventions to surgical procedures. In the case of mild to moderate knee OA, non-surgical treatment options are in good agreement and strongly supported by existing literature [1].  According to a 2021 consensus statement of 15 French-speaking physicians including PLYMOUTH MEDICAL client Dr. Martin Lamontagne [2], the following were determined to be appropriate with strong agreement:

  • A PRP treatment protocol may include 1-3 injections.

  • The volume of PRP injectate for knee OA should be 4-8 mL.

Although there is yet to reach a consensus on the optimal frequency and interval regimen for knee OA, the clinical studies and reviews below suggest:

  • Any PRP intervention (single or multiple injections) is effective for knee OA [1, 3-7]. Multiple injections (double or triple) interventions help to sustain clinical benefits up to one year post-treatment [1, 3-4].

  • Multiple injections of PRP outperform multiple injections of hyaluronic acid (HA) for early stages of knee OA [6]. 

  • For patients with advanced knee OA, PRP injections are effective in achieving clinical improvement, but there does not seem to be a significant difference regarding outcomes of single or multiple PRP injection protocols [7]. 

* P2 = PLT concentration is greater than baseline levels  to 750,000/microliter; B = WBC content is  below/equal to baseline levels [8]

** PLT concentration averages 3.8X baseline; WBC  = 200/microliter; RBC = 30,000/microliter [1]

***WBCs increased over baseline, > 5X platelets, Not activated [9]

Citations

[1] Ngarmukos, Srihatach, et al. “Two or Four Injections of Platelet-Rich Plasma for Osteoarthritic Knee Did Not Change Synovial Biomarkers but Similarly Improved Clinical Outcomes.” Scientific Reports, vol. 11, no. 1, 2021, https://doi.org/10.1038/s41598-021-03081-6. 

[2] Eymard, Florent, et al. “Intra-Articular Injections of Platelet-Rich Plasma in Symptomatic Knee Osteoarthritis: A Consensus Statement from French-Speaking Experts.” Knee Surgery, Sports Traumatology, Arthroscopy, vol. 29, no. 10, 2020, pp. 3195–3210., https://doi.org/10.1007/s00167-020-06102-5.

[3] Subramanyam, Koushik, et al. “Single versus Multi-Dose Intra-Articular Injection of Platelet Rich Plasma in Early Stages of Osteoarthritis of the Knee: A Single-Blind, Randomized, Superiority Trial.” Archives of Rheumatology, vol. 36, no. 3, 2021, pp. 326–334., https://doi.org/10.46497/archrheumatol.2021.8408. 

[4] Yurtbay, Alparslan, et al. “Multiple Platelet-Rich Plasma Injections Are Superior to Single PRP Injections or Saline in Osteoarthritis of the Knee: The 2-Year Results of a Randomized, Double-Blind, Placebo-Controlled Clinical Trial.” Archives of Orthopaedic and Trauma Surgery, 2021, https://doi.org/10.1007/s00402-021-04230-2.

[5] Vilchez-Cavazos, Félix, et al. “Comparison of the Clinical Effectiveness of Single versus Multiple Injections of Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review and Meta-Analysis.” Orthopaedic Journal of Sports Medicine, vol. 7, no. 12, 2019, p. 232596711988711., https://doi.org/10.1177/2325967119887116. 

[6] Tavassoli, Mehdi, et al. “Single- and Double-Dose of Platelet-Rich Plasma versus Hyaluronic Acid for Treatment of Knee Osteoarthritis: A Randomized Controlled Trial.” World Journal of Orthopedics, vol. 10, no. 9, 2019, pp. 310–326., https://doi.org/10.5312/wjo.v10.i9.310. 

[7] Görmeli, Gökay, et al. “Multiple PRP Injections Are More Effective than Single Injections and Hyaluronic Acid in Knees with Early Osteoarthritis: A Randomized, Double-Blind, Placebo-Controlled Trial.” Knee Surgery, Sports Traumatology, Arthroscopy, vol. 25, no. 3, 2015, pp. 958–965., https://doi.org/10.1007/s00167-015-3705-6. 

[8] DeLong, Jeffrey M., et al. “Platelet-Rich Plasma: The Paw Classification System.” Arthroscopy: The Journal of Arthroscopic & Related Surgery, vol. 28, no. 7, 2012, pp. 998–1009., https://doi.org/10.1016/j.arthro.2012.04.148. 

[9] Mautner, Kenneth, et al. “A Call for a Standard Classification System for Future Biologic Research: The Rationale for New PRP Nomenclature.” PM&R, vol. 7, 2015, https://doi.org/10.1016/j.pmrj.2015.02.005. 

07/01/22