The 50 Most Cited Publications in Adipose-Derived "Stem Cell Therapies" with Application in Orthopaedic Surgery

Stem cell therapies have become widely popular in orthopaedic surgery, with a recent interest in adipose-derived therapeutics. Adipose-derived mesenchymal signaling cells (ADSCs) and micronized adipose tissue (MAT) are unique therapies derived from different processing methods. Characterizing the most influential studies in lipoaspirate research can help clarify controversies in definitions, identify core literature, and further collective knowledge for educational purposes. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched to identify the top 50 most cited publications (based on citation/year) on orthopaedic ADSCs or MAT research. Publication and study characteristics were extracted and reported using descriptive statistics. Level of evidence was assessed for applicable studies, and Spearman correlations were calculated to assess the relationship between citation data and level of evidence. The top 50 articles were published between the years 2003 and 2020, with 78% published in the year 2010 or later. The mean number of citations was 103.1 ± 81.1. The mean citation rate was 12.4 ± 6.0 citations per year. Of the 21 studies for which level of evidence was assessed, the majority were level III (10, 47.6%). The single study design most common among the top 50 cited articles was in vitro basic science studies (17 studies, 34%). Twenty-nine articles (58%) were classified as basic science or translational. Application to treat knee osteoarthritis was the most common focus of studies (14 studies, 28%), followed by in vitro analysis of growth factor and cell signaling markers (11 studies, 22%). No correlation was found between rank, citation rate, or year of publication and level of evidence. This study provides a current landscape on the most cited articles in lipoaspirates in orthopaedic surgery. With the expansion of ADSCs and MAT in the past two decades, this study provides the first historical landmark of the literature and a launching point for future research. Studies should explicitly state their processing methodology and whether their study investigates ADSCs or MAT to avoid misinformation.