Platelet-Rich Plasma Therapy in Knee Osteoarthritis Management

Platelet-Rich Plasma (PRP) therapy has emerged as a promising orthobiologic intervention for knee osteoarthritis (OA), harnessing the patient’s own platelets and associated growth factors to modulate the joint environment. Prepared by centrifuging autologous blood to concentrate platelets above baseline levels, PRP is administered via intra-articular injection to deliver a high density of bioactive molecules directly into the joint space. These factors include platelet-derived growth factor, transforming growth factor-β and vascular endothelial growth factor, which collectively promote tissue repair, reduce inflammation and stimulate chondrogenesis. Clinical protocols vary in platelet dose, activation methods and adjunctive agents, yielding heterogeneity in composition and outcomes. Nevertheless, multiple studies have reported improvements in pain, function and quality of life, particularly in patients with mild to moderate OA. Advantages of PRP include its autologous origin, favourable safety profile and the potential to delay or avoid surgical intervention. Challenges remain in standardising preparation techniques, identifying optimal dosing thresholds and clarifying the relative roles of leukocyte-rich versus leukocyte-poor formulations. Recent consensus efforts and mechanistic studies are converging to inform evidence-based guidelines that can be implemented in routine clinical practice worldwide.

Research from Nature Portfolio

A foundational comparative study evaluated leukocyte-rich PRP (L-PRP) against pure PRP (P-PRP) in vitro and in vivo, revealing that P-PRP—with minimal white blood cell content—enhances proliferation and chondrogenic differentiation of mesenchymal stem cells more effectively than L-PRP. In a rabbit model of cartilage defect, implantation of bone marrow-derived mesenchymal stem cells combined with P-PRP produced superior histological repair and extracellular matrix quality. Mechanistic analyses indicated that removing leukocytes from PRP mitigates activation of the NF-κB inflammatory pathway, thereby optimising the regenerative milieu within the joint.

Platelet-Rich Plasma Therapy in Knee Osteoarthritis Management publication trend

The graph below shows the total number of articles in platelet-rich plasma therapy in knee osteoarthritis management across all publications each year (not limited to Nature Index journals).

Technical terms

Platelet-Rich Plasma (PRP): autologous plasma fraction containing a platelet concentration above baseline, enriched with growth factors and cytokines.

Leukocyte-rich PRP (L-PRP): PRP formulation retaining elevated white blood cell content, associated with pro-inflammatory mediators.

Pure PRP (P-PRP): PRP preparation minimised for leukocyte content to focus on regenerative signals.

Autologous: derived from the same individual, reducing immunogenic and transmissible risks.

Mesenchymal Stem Cells (MSCs): multipotent stromal cells capable of differentiating into chondrocytes, osteoblasts and other lineages.

Intra-articular injection: direct delivery of a therapeutic agent into the joint cavity to target articular structures.

References

1. Exploring Platelet-Rich Plasma Therapy for Knee Osteoarthritis: An In-Depth Analysis. Journal of Functional Biomaterials (2024).
2. The Effect of Platelet Dose on Outcomes after Platelet Rich Plasma Injections for Musculoskeletal Conditions: A Systematic Review and Meta-Analysis. Current Reviews in Musculoskeletal Medicine (2024).
3. The use of injectable orthobiologics for knee osteoarthritis: A European ESSKA‐ORBIT consensus. Part 1—Blood‐derived products (platelet‐rich plasma). Knee Surgery, Sports Traumatology, Arthroscopy (2024).
4. Biology of platelet-rich plasma and its clinical application in cartilage repair. Arthritis Research & Therapy (2014).
5. Comparative evaluation of leukocyte- and platelet-rich plasma and pure platelet-rich plasma for cartilage regeneration. Scientific Reports (2017).