The study analyzed 20 years of research on platelet-rich plasma (PRP) in the treatment of osteoarthritis using a bibliometric analysis of the Web of Science database. Research came primarily from the United States (1,675 publications) and China (1,310 publications), with the number of publications increasing significantly since 2012. The leading research institutions were the Rizzoli Orthopedic Institute, Hospital for Special Surgery, and Rush University, and the most prolific author was Giuseppe Filardo. Research initially focused on the regeneration of damaged tissue, but has gradually shifted to understanding immunomodulatory mechanisms, particularly the regulation of macrophage phenotypes and inflammatory mediators. The study identified four main areas of research: disease targets and tissue mechanisms, pathophysiological processes, comparative clinical treatments and research methodologies. The authors recommend that future research prioritize standardization of PRP protocols based on their immunomodulatory potential and further investigation of strategies to manipulate the inflammatory joint environment.