Influential Studies in Orthopaedic Platelet-Rich Plasma Research Are Recent and Consist of High Levels of Evidence: A Review of the Top 50 Most Cited Publications

Platelet-rich plasma (PRP) has garnered widespread and increasing attention in recent years. We aimed to characterize the most influential articles in PRP research while clarifying controversies surrounding its use and clinical efficacy and identifying important areas on which to focus future research efforts. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched to identify the top 50 cited publications on orthopedic PRP research. Publication and study characteristics were extracted, and Spearman's correlations were calculated to assess the relationship between citation data and level of evidence. The top 50 articles were published between the years 2005 and 2016, with 68% published in the year 2010 or later. Of the 33 studies for which level of evidence was assessed, the majority were of level I or II (18, 54.5%). Seventeen articles (34%) were classified as basic science. All clinical studies were prospective, and most (12 studies, 60%) included a high number of metrics related to the PRP preparation protocol and composition. Knee osteoarthritis was the most common topic among clinical studies in the top 50 cited articles (11 studies, 34%). More recent articles were associated with higher citation rates ( rho = 0.46, p < 0.001). The most influential articles on orthopaedic PRP research are recent and consist of high-level of evidence studies mostly. Randomized controlled trials were the most common study type, while basic science articles were relatively less common. The most influential clinical studies reported a high number of metrics related to their PRP preparation protocol and the final PRP composition. These results suggest a rapidly evolving field with the potential to better explain inconsistent clinical results with improved understanding and documentation of basic science concepts such as PRP composition, preparation, and combination techniques.