Item Price Qty Total
Your shopping cart is empty.
Item Price Qty Total
Loading Cart...

Is PRP an Effective Treatment for Knee Osteoarthritis?

Published: 07/20/2022

Knee osteoarthritis (KOA) is a painful and debilitating condition affecting a large number of patients worldwide. KOA is characterized by a progressive loss of articular cartilage and inflammation. Due to the destructive nature of osteoarthritis and its effects on patients, research on platelet-rich plasma (PRP) therapy is increasing.

In this article, we review the latest research and clinical trials on PRP's effectiveness in KOA.

About PRP in KOA Treatment

PRP contains concentrated platelets rich in a complement of growth factors and anti-inflammatory cytokines that are responsible for healing. This complement induces:

  • Growth in number of cells
  • Directed movement of cells for tissue renewal and repair
  • Cell specialization for different functions
  • Development of new blood vessels
  • Formation of the extracellular matrix

PRP is also known to have a modulating effect on pro-inflammatory mediators and catabolic enzymes. These qualities have made PRP a promising therapeutic option for osteoarthritis.

More and more studies are confirming that PRP IA (intra-articular) injections are more effective and safer than NSAIDs due to their ability to actually regenerate tissue in damaged structures. PRP IA injections are a good option for patients who haven't responded to conservative treatment, but don't require surgery.

PRP Injections are Effective at Reducing Inflammation and Pain in OA Animal Models

There are several questions regarding PRP administration that have been studied in animal models.

  1. The frequency of PRP administration. A study using a guinea pig model investigated whether three injections of leukocyte-poor PRP was superior to a single injection. The researchers of this study concluded that multiple PRP injections were better at reducing long-term inflammation. 1
    A study using mice confirmed the results above. The research team observed that multiple PRP IA injections reduced synovial inflammation and protected the cartilage while alleviating pain. 2
  2. The leukocyte content of PRP. A rat arthritis model showed that intra-articular injections of pure PRP was more effective than leukocyte-rich PRP for inhibiting the progression of synovitis and reduction of pain.3

These animal models can help researchers and physicians with clinical decisions in their use of PRP.

PRP Injections Improve Symptoms of KOA in Human Clinical Trials

Animal models do not always translate into routine clinical practice. Fortunately, researchers are gaining more understanding of the molecular functions of PRP that affect KOA treatment outcomes in patients.

One study compared the effects of PRP to hyaluronic acid (HA) in patients with mild to moderate OA. Synovial fluid (SF) from each patient was analyzed for pro-inflammatory and anti-inflammatory markers. Patients in the PRP group reported greater improvements in their pain and saw significant decreases in two pro-inflammatory cytokines (IL-1β and TNF-α) compared to the HA group.4

Some researchers oppose the use of leukocyte-pure PRP in KOA treatment. They argue that some leukocytes release both pro- and anti-inflammatory molecules, and that the combination of these molecules and activated platelets enhances regenerative qualities.5

Another issue regarding PRP treatment in OA is whether to use PRP alone or in combination with HA. One study compared the effectiveness of a PRP and HA combination to PRP alone and HA alone for the treatment of patients with mild to moderate KOA.6 At 24 months, the results showed that the PRP and HA combination was more effective than either treatment alone at inhibiting synovial inflammation. Patients receiving the combination also reported improved pain and function and reduced adverse reactions.

Another study suggested that PRP injections in the intra-articular (IA) space may not be enough for geriatric patients with KOA. In this study, patients were divided into two treatment groups - PRP IA injection (Group 1) and simultaneous PRP IA and PRP pes anserinus injections (Group 2). Both groups revealed positive changes, including an increase in anti-aging proteins. However, only Group 2 showed improvements in knee function and inflammation markers. 7

Clearly, PRP is a safe and effective treatment for knee osteoarthritis. Numerous studies show that PRP helps control pain, reduce inflammation, protect cartilage, and restore function of the knee.

A Promising Solution for Knee Osteoarthritis Treatment

A growing body of evidence shows that PRP therapy offers a simple and minimally-invasive technique to restore the structure and function of the knees.

Dr. PRP offers complete, affordable systems to help you incorporate PRP into your practice. Our patented design ensures consistent results for your patients and your practice. View Dr. PRP kits and PRP centrifuges at our online store.

Got questions? We're happy to answer them. Contact us today at 844-377-7787 (DR-PRP-US).


  1. Chouhan DK, Dhillon MS, Patel S, Bansal T, Bhatia A, Kanwat H. Multiple Platelet-Rich Plasma Injections Versus Single Platelet-Rich Plasma Injection in Early Osteoarthritis of the Knee: An Experimental Study in a Guinea Pig Model of Early Knee Osteoarthritis. The American Journal of Sports Medicine. 2019;47(10):2300-2307. doi:10.1177/0363546519856605
  2. Khatab S, van Buul GM, Kops N, Bastiaansen-Jenniskens YM, Bos PK, Verhaar JA, van Osch GJ. Intra-articular Injections of Platelet-Rich Plasma Releasate Reduce Pain and Synovial Inflammation in a Mouse Model of Osteoarthritis. Am J Sports Med. 2018 Mar;46(4):977-986. doi: 10.1177/0363546517750635. Epub 2018 Jan 26. PMID: 29373806.
  3. Araya N, Miyatake K, Tsuji K, et al. Intra-articular Injection of Pure Platelet-Rich Plasma Is the Most Effective Treatment for Joint Pain by Modulating Synovial Inflammation and Calcitonin Gene-Related Peptide Expression in a Rat Arthritis Model. The American Journal of Sports Medicine. 2020;48(8):2004-2012. doi:10.1177/0363546520924011
  4. Cole BJ, Karas V, Hussey K, Merkow DB, Pilz K, Fortier LA. Hyaluronic Acid Versus Platelet-Rich Plasma: A Prospective, Double-Blind Randomized Controlled Trial Comparing Clinical Outcomes and Effects on Intra-articular Biology for the Treatment of Knee Osteoarthritis. The American Journal of Sports Medicine. 2017;45(2):339-346. doi:10.1177/0363546516665809
  5. Lana JF, Macedo A, Ingrao ILG, Huber SC, Santos GS, Santana MHA. Leukocyte-rich PRP for knee osteoarthritis: Current concepts. J Clin Orthop Trauma. 2019;10(Suppl 1):S179-S182. doi:10.1016/j.jcot.2019.01.011
  6. Zhe Xu, M.D., Zhixu He, Ph.D., Liping Shu, Ph.D., Xuanze Li, M.D., Minxian Ma, M.D., Chuan Ye, Ph.D., Intra-Articular Platelet-Rich Plasma Combined With Hyaluronic Acid Injection for Knee Osteoarthritis Is Superior to Platelet-Rich Plasma or Hyaluronic Acid Alone in Inhibiting Inflammation and Improving Pain and Function. The Journal of ARthroscopic and Related Surgery. VOLUME 37, ISSUE 3, P903-915, MARCH 01, 2021. DOI:
  7. Carl P.C. Chen, Jean-Lon Chen, Chih-Chin Hsu, Yu-Cheng Pei, Wei-Han Chang, Hsueh-Chih Lu, Injecting autologous platelet rich plasma solely into the knee joint is not adequate in treating geriatric patients with moderate to severe knee osteoarthritis, Experimental Gerontology, Volume 119, 2019, Pages 1-6, ISSN 0531-5565,