From the Guidelines
Growth factors, particularly platelet-rich plasma (PRP) therapy, have shown promise in treating knee osteoarthritis, but the current evidence is inconsistent, and their use is not universally recommended. The most recent and highest quality study, published in 2022 1, found that PRP therapy had some benefits in reducing pain and improving function in patients with knee osteoarthritis, but the evidence was not strong enough to support its routine use.
Key Points
- PRP therapy involves the injection of concentrated platelets from the patient's own blood directly into the knee joint, with potential benefits lasting 6-12 months.
- Other growth factor treatments, such as bone marrow aspirate concentrate (BMAC) and adipose-derived stem cells, may also be effective in stimulating cartilage repair.
- These treatments work by releasing proteins like transforming growth factor-beta (TGF-β), insulin-like growth factor (IGF), and vascular endothelial growth factor (VEGF) that reduce inflammation, stimulate chondrocyte proliferation, and enhance matrix synthesis in damaged cartilage.
- Patients with mild to moderate osteoarthritis (Kellgren-Lawrence grades 1-3) may be more likely to benefit from growth factor treatments, while those with advanced disease may not respond as well.
- The cost of PRP therapy can range from $500-$2,000 per injection, and it is often not covered by insurance.
- To optimize results, patients should continue prescribed physical therapy and avoid anti-inflammatory medications for 2 weeks following treatment.
Considerations
- The evidence for growth factor treatments in knee osteoarthritis is not yet strong enough to support their routine use, and more research is needed to fully understand their benefits and risks.
- Patients should discuss the potential benefits and risks of growth factor treatments with their healthcare provider to determine if they are a good candidate for this type of therapy.
- Other treatment options, such as weight loss, exercise, and oral medications, shouldn't be overlooked and may be more effective for some patients 1.
From the Research
Significance of Growth Factors in Treating Osteoarthritis
- Growth factors, such as PDGF-BB, play a crucial role in treating osteoarthritis (OA) of the knee, as they stimulate growth and inhibit joint damage 2.
- Platelet-rich plasma (PRP) contains growth factors and has become a promising treatment for knee OA, enhancing articular cartilage regeneration and reducing OA-related impairment 2, 3, 4.
- Studies have shown that multiple PRP injections are safe and associated with elevated growth factor levels, reduced pain, and improved clinical outcomes in patients with knee OA 2, 3, 4.
Mechanism of Action
- Growth factors in PRP, such as PDGF-BB, TGF-β1, and others, work by reducing inflammation, promoting cartilage regeneration, and inhibiting joint damage 2, 3, 4.
- The combination of PRP with other treatments, such as physical therapy or hyaluronic acid injections, may enhance the effectiveness of PRP in treating knee OA 3, 5.
Clinical Evidence
- Randomized controlled trials have demonstrated the efficacy of PRP injections in improving clinical outcomes, such as pain and function, in patients with knee OA 2, 3, 4.
- Studies have also shown that the concentration of growth factors in PRP is associated with clinical outcomes, highlighting the importance of optimizing PRP preparation and administration protocols 4.
- Intraosseous and intraarticular injections of PRP, combined with hyaluronic acid, have also shown promising results in improving functional outcomes and reducing pain in patients with knee OA 6, 5.