Intra Articular Injections with MSCs and PRP for Knee Osteoarthritis

Knee osteoarthritis is a chronic progressive disease affecting more than 20% of people older than 45 years, involving progressive degeneration of the articular cartilage and subchondral bone, often accompanied by synovitis. 

Different treatments have been used over the years, including conservative therapies such as anti-inflammatory drugs, physical therapy and joint injections (i.e. steroids, hyaluronic acid), or surgical procedures. However, nonsurgical options only provide short-term efficacy and surgical procedures are invasive with potential complications. 

One alternative therapy that has been studied over recent years is the use of biologics such as mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP). MCSs can be derived from multiple sources including bone marrow, fat tissue, and umbilical cord, and possess anti-inflammatory and regenerative capabilities that current therapies lack. On the other hand, PRP can also release a high concentration of a wide range of growth factors that play an important role in tissue repair. 

In a study by Bastos and colleagues, published in the journal Knee Surgery, Sports Traumatology, Arthroscopy, researchers evaluated the use of both biologics in the treatment of knee osteoarthritis. 

MSCs vs MSCs + PRP

To do so, the team included 18 participants in their study with radiographic symptomatic knee osteoarthritis that were randomized to receive intra-articular injections of MSCs (9 participants), or MSCs and PRP (9 participants).

The injections were performed 2-3 weeks after the bone marrow aspiration was performed. The samples of bone marrow were cultured and expanded in the laboratory. 

During the 12 months of follow-up, all other therapies were prohibited, including medications such as NSAIDs, hydrotherapy, heat, ultrasound, or acupuncture. 

The patients attended follow-up visits at 1, 2, 3, 6, 9, and 12 months after the procedure was performed. The Osteoarthritis Outcome Score (KOOS) questionnaire was used as an evaluation tool. 

The KOOS score improved significantly throughout the 12 months for both MSCs and MSCs + PRP groups. Both had significant improvement in the pain, function, daily living activities, and sports and recreational activities. There were no significant differences between the groups. 

Intra-articular injections of expanded MSCs alone, or in combination with PRP led to improvements of 22.6 and 26.4 points in the KOOS global score at 12 months. 

As we can see the results of the study were promising and can support the recommendation of this minimally invasive procedure in patients with osteoarthritis. 


Bastos, R., Mathias, M., Andrade, R. et al. Intra-articular injections of expanded mesenchymal stem cells with and without addition of platelet-rich plasma are safe and effective for knee osteoarthritis. Knee Surg Sports Traumatol Arthrosc 26, 3342–3350 (2018). 

Image from: 

Photo by Towfiqu barbhuiya: