Consensus on Platelet-Rich Plasma Injections for Knee Osteoarthritis

Overview

A French-speaking expert group developed a consensus on the use of platelet-rich plasma (PRP) injections for symptomatic knee osteoarthritis (OA). Despite international societies advising against PRP due to insufficient robust data and heterogeneity, this consensus synthesizes literature and expert experience to provide 25 recommendations aimed at standardizing clinical practice.

Background

Platelet-rich plasma (PRP) is an autologous blood product enriched in platelets that release numerous growth factors and anti-inflammatory mediators potentially beneficial in knee OA. Preclinical studies suggest PRP has anabolic and anti-inflammatory effects on joint tissues. However, international guidelines from bodies like ACR and OARSI currently do not recommend PRP for knee OA due to limited high-quality evidence and variability in preparation and administration protocols. To address these issues, a group of French-speaking experts convened to review the literature and clinical experience to develop consensus recommendations to guide PRP use in knee OA.

Data Highlights

The expert panel conducted a comprehensive literature review including randomized controlled trials, placebo-controlled studies, and meta-analyses comparing PRP to placebo or hyaluronic acid (HA). Placebo-controlled trials showed PRP efficacy superior to saline over 3 to 12 months. Trials comparing PRP to HA suggested at least equivalent or greater efficacy of PRP. However, heterogeneity in PRP preparation methods, injection protocols, and post-injection management limited extrapolation. The consensus process involved 15 experts from 5 countries, who reviewed 43 initial recommendations, ultimately endorsing 25 after multiple rounds of voting and refinement.

Key Findings

• PRP contains multiple growth factors (e.g., TGFβ, PDGF, VEGF) and anti-inflammatory cytokines (e.g., IL-1RA, IL-4, IL-10) that may mediate therapeutic effects in knee OA.
• Preclinical evidence supports PRP's anabolic and anti-inflammatory actions on joint tissues.
• Placebo-controlled clinical trials demonstrate PRP's superiority over saline in symptom relief up to 12 months.
• Randomized trials comparing PRP to hyaluronic acid suggest PRP is at least as effective or more effective for symptomatic knee OA.
• Significant heterogeneity exists in PRP preparation (centrifugation methods, leukocyte content), injection number and volume, and post-injection care, complicating interpretation of results.
• The consensus process led to 25 recommendations to standardize PRP use, including indications, preparation, contraindications, and post-injection management.

Clinical Implications

Clinicians should consider PRP as a treatment option for symptomatic knee OA, recognizing its potential benefits demonstrated in controlled trials. Standardization of PRP preparation and administration protocols is essential to optimize outcomes and reduce variability. The consensus recommendations provide practical guidance to harmonize clinical practice and avoid misuse of PRP injections in knee OA.

Conclusion

This expert consensus synthesizes current evidence and clinical experience to provide standardized recommendations for PRP use in symptomatic knee osteoarthritis. It aims to guide practitioners in optimizing treatment efficacy and safety despite existing heterogeneity in protocols.

References

1. French-Speaking Expert Group 2020 -- Consensus Statement on PRP for Knee Osteoarthritis