Abstract
Objectives:
To identify the top 100 most impactful anterior cruciate ligament articles in online media as measured by the Altmetric Attention Score and compare their characteristics to the most-cited anterior cruciate ligament articles in the scientific literature.
Methods:
The Altmetric database was queried to identify all published articles pertaining to the anterior cruciate ligament. The search yielded 9445 articles, which were stratified by highest to lowest Altmetric Attention Score. The top 100 articles were included. Collected data included article type, article topic, journal name, and online mentions in news, blogs, Twitter, Facebook, Wikipedia, and other sources. The geographic origin of each article was also determined based on the institutional affiliation of the first author.
Results:
Altmetric Attention Score of the top 100 anterior cruciate ligament articles ranged from 109 to 2193 (median 172.0, interquartile range 137.5–271.5). Of the 100 articles, 65 were published in three journals: American Journal of Sports Medicine, British Journal of Sports Medicine, and Journal of Orthopaedic & Sports Physical Therapy. The most prevalent article type was original research (60%), followed by systematic review/meta-analysis (18%). The most prevalent article topic was rehabilitation and return to play after anterior cruciate ligament reconstruction (22%), followed by epidemiology/risk factors (16%), injury prevention (14%), and biomechanics of anterior cruciate ligament injuries (14%). Of the top 100 articles, 54% were American, 31% were European, and 15% were published in other countries outside of the United States and Europe.
Conclusion:
This study used Altmetric Attention Score to identify the 100 most engaged anterior cruciate ligament articles in online media. The characteristics of these articles differed substantially from the most-cited anterior cruciate ligament articles in the literature with regard to article type, article topic, geographic origin, and publication journal. These findings suggest that alternative metrics measure distinct components of anterior cruciate ligament article engagement and add an important dimension to understanding the overall impact of published research on the anterior cruciate ligament.
Keywords
Introduction
Bibliometric analysis has been used to assess the academic impact of various types of orthopedic research.1 –8 This type of analysis provides insight into the value of specific articles within various scientific communities and is a growing trend in other medical specialties in the last 5 years, including medical imaging, gastroenterology, and neurosciences.9 –11 However, social media platforms, such as Twitter, are increasingly used as a means of disseminating scientific research, and conventional bibliometrics do not account for the engagement of physicians and scientists with academic research that occurs in the online setting.12 –14 Overall, little is known about the proliferation of orthopedic research in online media.
Previous studies have used the Altmetric Attention Score (AAS) to examine the most mentioned articles in online media pertaining to other medical specialties, such as cardiology, 15 neurology, 16 and spine surgery, 17 but no study has reported the online engagement of articles pertaining to a particular topic in sports medicine. The anterior cruciate ligament (ACL) is one of the most commonly injured ligaments in the human body, 18 with over 120,000 ACL injuries occurring annually in the United States and peak incidence in high school athletes. 19 The implications of ACL injuries in the realm of competitive athletics may generate a robust online discussion surrounding ACL research that has not yet been captured or quantified in a systematic way.
The purpose of this study was to use an established alternative metrics database to evaluate the online engagement of ACL research articles. We aimed to identify the 100 most engaged ACL articles in online media as measured by the AAS and compare their characteristics to the most-cited ACL articles in the literature. Our goal was to achieve a better understanding of the online dissemination of ACL research as an added dimension of ACL research impact.
Methods
The Altmetric database (Altmetric.com), which tracks online attention generated by a research article 20 and calculates a quantitative AAS, was queried on 17 June 2020, to identify articles pertaining to the ACL. The search was performed using the PubMed MeSH terms “ACL” or “anterior cruciate ligament” and yielded 9445 articles published between 2005 and 2020. These articles were stratified by highest to lowest AAS, and the 100 articles with the highest scores were included for analysis. All articles that focused on other orthopedic topics were sequentially excluded until 100 relevant articles were gathered.
Collected data included title, authors, year of publication, journal name, institutional affiliations, article type, article topic, and online mentions (e.g. the number of times the article was mentioned in news, blogs, Twitter, Facebook, and Wikipedia). Article type was identified from the article abstract and classified as original research (further subclassified as randomized controlled trial, prospective cohort, retrospective cohort, case–control, case series, case report, or laboratory study), descriptive epidemiology, systematic review/meta-analysis, review, editorial/expert opinion, clinical commentary, or other. Article topics were classified as anatomy, basic science, biomechanics, cost, diagnostics, treatment, neuromechanics, epidemiology/risk factors, injury prevention, rehabilitation/return to play, patient satisfaction/quality of life, or other. The geographic origin of the article was determined by the institutional affiliation of the first author, categorized as American (originating in the United States), European (originating in Europe), or other.
Statistical analysis
STATA 15.1 (STATACorp) was used for calculations and statistical analysis. Median and quartiles were calculated for AAS. Spearman correlation and logarithmic regression were used to determine the relationship between online mentions and AAS, and analysis of variance (ANOVA) was used to determine whether article type or topic was associated with AAS. All calculations were performed at a significance level of
Results
The AAS of the top 100 ACL articles ranged from 109 to 2193 (median 172.0, interquartile range (IQR) 137.5–271.5) (Table 1). (In context, the highest AAS in medical and health sciences in 2019 belonged to an article published in Nature entitled “Scientists rise up against statistical significance,” yielding an AAS of 13,155.) The selected articles were published in 27 journals. Three journals accounted for 65 of the 100 articles: American Journal of Sports Medicine (AJSM) (34 articles), British Journal of Sports Medicine (BJSM) (21 articles), and Journal of Orthopaedic & Sports Physical Therapy (JOSPT) (10 articles). The Journal of Bone and Joint Surgery (JBJS) was represented by one article, and other established orthopedic journals also had lower representation on the list.
Top 100 most influential ACL articles by Altmetric Attention Score (AAS).
AAS: Altmetric Attention Score; ACL: anterior cruciate ligament.
Among the 100 selected articles, the most prevalent article type was original research (60%), of which prospective cohort study was the most common subgroup (40%; 24/60) (Figure 1(a), (b)). Systematic review/meta-analysis was the next most common article type (18%; 18/100). Three review articles discussed more than one topic, which resulted in a total of 105 article topics for the 100 included articles. The most prevalent article topic was rehabilitation and return to play after ACL reconstruction (22%; 23/105), followed by epidemiology/risk factors (16%; 17/105), injury prevention (14%; 15/105), and biomechanics of ACL injuries (14%; 15/105) (Figure 2). Fifty-four percent of the included articles were American, 31% were European, and 15% were published in other countries outside of the United States and Europe. Article type, topic, and geographic origin were not significantly associated with AAS (all
(a) A representation of the types of articles comprising the top 100 articles related to the ACL by Altmetric Attention Score (AAS); (b) Representation of article subtypes of the Original Research article type.
Characteristics of the article topics within the top 100 articles pertaining to the ACL according to Altmetric Attention Score (AAS).
Among the 100 most engaged articles, there were 37,801 Twitter mentions (median 259.5, IQR 183.0–421.5), 1765 Facebook mentions (median 8.0; IQR 4.0–17.5), and 735 mentions in online news outlets (median 1.0; IQR 0–3.0). Among online media sources, YouTube video description mentions (r = 0.78, R 2 = 0.60) correlated most strongly with AAS, followed by Twitter mentions (r = 0.75, R 2 = 0.56) and blog mentions (r = 0.75, R 2 = 0.56).
Discussion
Although some of the online discussion surrounding ACL research occurs among members of the general public who follow or report on sports, social media is also being used increasingly by orthopedic surgeons for general discussion 121 and educational purposes. 122 The results of this study suggest that the online dissemination of ACL research adds an important dimension to the online engagement of published articles pertaining to the ACL. Our findings support the use of alternative metrics as a supplement to conventional bibliometrics in order to achieve a more complete assessment of the overall impact of ACL research within the academic community.
Among the 100 most mentioned ACL articles identified in this study, original research was the most prevalent article type and the most common topics were rehabilitation/return to play, epidemiology/risk factors, and injury prevention. Online interest in ACL research was broad, with no association observed between article type, topic, or geographic origin and AAS. Three specialty-specific sports medicine journals (AJSM, BJSM, and JOSPT) accounted for 65% of the 100 articles. Our data suggest that the topics most talked about online tend to be American studies published in sports medicine journals that focus on practical concerns related to the effect of ACL injury on athletic participation.
Our findings pertaining to article topic contrast with a previous report of the 50 most-cited ACL articles, in which the most common topics were anatomy/biomechanics (38%) and surgical technique (26%). 18 The readership of sports medicine journals, comprised predominantly of orthopedic surgeons and other musculoskeletal healthcare providers, may be likely to view the aspects of ACL injury that fall within their domain as the most important: understanding the anatomical and biomechanical factors underlying the injury and providing the optimal surgical treatment. In online media, however, attention appears to be focused on the aspects of ACL rupture that directly impact an athlete’s ability to perform.
Citation rate has been shown to have no correlation to AAS, 123 supported in our study by the incongruence in the article topics and types that constitute to the most impactful articles as determined by AAS or citation rate. Compared with previous studies that examined the most impactful ACL articles by citation density,18,124 the results of the present study demonstrate a predominance of clinically focused studies and a relatively lower degree of interest in laboratory studies. This finding is congruent with the historical trend of ACL research toward higher levels of evidence. 125 Among the 100 ACL articles with the highest AAS, the most common article type was original research (Figure 1(a)), and basic science studies accounted for just 10% of these articles (Figure 1(b)). By comparison, basic science accounted for a higher proportion of studies (42% and 36%, respectively) in previous reports on the 50 most-cited ACL articles.18,124 One possible explanation for this finding is that laboratory findings, which are farther removed from the clinical setting, may hold less interest to an online audience that is more focused on ACL research with immediate clinical relevance.
The current findings also suggest that the online distribution of ACL research may facilitate broader access to readership compared with traditional citation-based methods. In their previous studies of the most-cited ACL articles, Vielgut et al. and Voleti et al. reported a strong predominance of American publications (80% and 68%, respectively), followed distantly by studies originating in Europe (16% and 18%, respectively).18,124 A predominance of highly cited articles originating in the United States is not unique to the ACL literature and has been demonstrated in other topics related to orthopedic, general, and plastic surgery.126 –128 By comparison, a greater proportion of articles in the present study (46%) originated outside the United States, with nearly one-third of all articles being European in origin and 15% originating from other countries outside the United States and Europe. BJSM articles accounted for 21% of the top 100 ACL articles in this study, and four of the top five ACL articles with highest AAS originated in Europe.
There are many considerations to address before using Altmetric as a standalone metric of article impact. Although social media attention provides a benchmark of article attention, the AAS could be used deliberately to promote some publications over others. 129 Moreover, the AAS for individual articles could be manipulated by utilizing Twitter bots 130 or through self-promoting online journal clubs. 131 There are other internal factors of Altmetric to consider, including its dynamic nature which has the potential to produce a different list of top 100 articles depending on which date the search is performed. In addition, articles published in the years preceding Altmetrics release in 2012 are likely to have lower AAS. 32 The Altmetric algorithm itself is not publicly available, giving question to internal bias or shortcomings to adequately capture every online mention which constitutes to an article’s AAS. Finally, Altmetric does not account for the content of the online conversation or the positive or negative nature of the conversation.132 –135 Thus, the articles with highest AAS scores may not indicate high study quality or scientific importance.
Conclusion
The 100 most impactful online ACL articles, as measured by AAS, differed substantially from the most-cited ACL articles in the literature with regard to article type, article topic, geographic origin, and publication journal. These findings suggest that alternative metrics measure distinct components of ACL article engagement and add an important dimension to understanding the overall impact of published research on the ACL.
Footnotes
Author contributions
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
