Efficacy of Platelet-Rich-Plasma Injection for Knee Osteoarthritis: A Review Article of Clinical Evidence

Abstract

Background: Osteoarthritis (OA) is a chronic and degenerative disease which is mostly seen in adult population. It is common form of joint disability which negatively affect the quality of life of affected people. This study was conducted to review evidence on the use of platelet-rich-plasma (PRP) injection for treatment knee OA, evaluating its efficacy, limitations, and geographical disparities in research.                                                       .
Methods: This review encompassed 39 eligible studies: 11 meta-analyses, 10 RCTs, seven systematic reviews, seven narrative reviews, and four observational studies. It examined key themes such as the comparative efficacy of PRP versus HA, CS, and placebo injection; protocol variability; and long-term outcomes.                                             .
Results: Applying PRP at early stages and in mid-term (6-12 months) demonstrates significant superiority over HA and steroids in pain reduction and functional improvement, particularly in early-to-moderate OA. However, structural benefits such as cartilage regeneration remain unproven, as well as evidence beyond 24 months is limited. Critical limitations include protocol heterogeneity as leukocyte content, centrifugation methods, statistical fragility in meta-analyses, and publication bias favoring small positive trials. Over 90% of studies originated from high-income countries particularly USA, China, and Europe, while people affected with severe OA and low income countries and regions with constrained resources remained underrepresented.                                                               .
Conclusion: The PRP effectiveness and its feasibility as a second-line therapy for early and moderate cases of knee joint OA confirmed, but its long-term efficacy and cost-effectiveness require further validation. There is a need for conducting RCTs to examine its efficacy after follow-up in longer term (≥3 years).  Addressing geographical disparities through inclusive research is recommended.