Four Decades of Foot and Ankle Research Activity: A Scientometric study of Subspecialty Foot and Ankle Journals

Objectives: To evaluate foot and ankle documents using scientometric methods and provide insight into global research activities. Methods: This scientometric study was conducted at the Department of Spine Surgery, Ganzhou People’s Hospital, China. Documents on foot and ankle from 1980 to 2019 were retrieved from the Scopus database. The number of documents, year of publication, journal, country, institution, author, h-index, and top-cited documents were analyzed. Results: In total, 11313 documents were retrieved. The annual research output on foot and ankle showed a dramatic increase over the past four decades, especially in the past decade (p = 0.000). Foot & Ankle International published the biggest number of documents (44.48%). The United States contributed more than half (52.17%) of the global production, followed by the United Kingdom (11.39%), and Germany (3.62%). The United States had the highest h-index (109). The Hospital for Special Surgery (1.87%) ranked first in terms of productivity, followed by Union Memorial Hospital (1.37%), and Duke University Medical Center (1.24%). The most productive author was Myerson MS (1.25%), followed by Schon LC (0.77%), and Hyer CF (0.74%). Conclusion: Research on foot and ankle has thrived rapidly over the past four decades, particularly in the last decade. The United States contributes the most to the quantity and quality of foot and ankle documents.


INTRODUCTION
Foot and ankle surgery has become a critical subspecialty in the field of orthopedics. This might be attributed to the rapid progress of foot and ankle research. [1][2][3][4][5][6][7][8] In light of the impact of foot and ankle research and in light of differences in medical policy and health services, the need to evaluate foot and ankle research has become crucial. [9][10][11][12][13][14][15] Publication is an important index of the conception of new knowledge, and is also an important method for scientific communication. [3][4][5][6][7][8][16][17][18] Scientometrics involve metrological approaches for the quantitative and qualitative analysis of scientific documents. 4,7 Scientometric study is a vital element in establishing baseline data for future comparisons in certain fileds. 4,7,8 Scientometric analysis can provide information such as publication trends and the characteristics of documents, counties, institutions, and authors. 4-6 It helps understand their different contributions, and can be used to identify research gaps that future efforts could focus on. 3,5,6,19 Scientometric analysis of research activity is widely used to determine the characteristics of documents on various topics. [3][4][5][6][7][8] However, scientometric studies on foot and ankle publications are limited. Therefore, the goal of the current study was to perform

Original Article
Four Decades of Foot and Ankle Research Activity: A Scientometric study of Subspecialty Foot and Ankle Journals a comprehensive analysis of publications on foot and ankle research using a scientometric method during the period 1980-2019.

METHODS
This scientometric study was conducted at the Department of Spine Surgery, Ganzhou People's Hospital, China. This study does not involve animals or humans, and ethical approval was not required. The method and indicators chosen in the current study have been explained in detail in similar scientometric studies. [3][4][5][6][7][8] To achieve the goal of the study, we also used the Scopus database to identify documents on the foot and ankle. [3][4][5][6][7][8] Scopus is one of the largest electronic databases for literature research and scientometric analysis. 8 It has the ability to provide details on journals, citations, countries, institutions, authors, h-index, and other information based on search results. [4][5][6] Another advantage is that it has a higher number of journals than PubMed and Web of Science. 20 Scopus contains information for documents published in more than 21,500 titles from more than 5000 international publishers, including Medline. 20 In addition, Scopus has multiple analytic functions that facilitate scientometric investigations of retrieved documents. [4][5][6]8 Therefore, Scopus has been used in numerous previous publications in diverse fields. [3][4][5][6][7][8] Five international subspecialty journals on foot and ankle, listed in the Journal Citation Reports, were included as literature sources, which were. 8 Information on the number of documents, journals, countries, institutions, year of publication, h-index, and top-cited documents was collected and analyzed. The h-index was used to determine the document quality. A higher h-index suggests that documents had a greater influence. Scopus provided an h-index value for any set of documents. The h-index is an indicator of the importance of the authors in a particular field. However, the use of the h-index has been extended to evaluate the research activity and citation importance of a country or institution. 22 A country, institution, or author with an h-index of n indicates that the country, institution, or author has a minimum of n documents receiving at least n citations. 8,22 In addition, in terms of research activity, the 10 most productive countries, institutions, authors, and the 10 most cited documents were analyzed. Regression analysis was performed to determine the significance of the trends between 1980 and 2019. Statistical analysis was performed using SPSS version 22.0 (SPSS Inc., Chicago, IL, USA). Statistical significance was set at p<0.05. Table-I Table-II Table-III).

Information on the included journals is presented in
The top 10 productive authors on the foot and ankle are shown in Table-

DISCUSSION
In the present study, we sought to provide a scientometric overview of the research on the foot and ankle over the past four decades. Thus, we used the well-known Scopus database, which has been widely used in previous scientometric studies. [3][4][5][6][7][8] Our study found that documents on foot and ankle increased rapidly over the past four decades, particularly in the past decade. The United States was the most active country, and had the highest quality of documents in terms of the h-index. Foot & Ankle International, with nearly half of all documents, was the most active journal. This is the first established journal in the five foot and ankle journal.
This might be attributed to the large number of documents in Foot & Ankle International. 4,8,23 Moreover, Foot & Ankle International had the highest impact factor. These results suggest that the documents published in Foot & Ankle International in large quantities were also of high quality. Our findings demonstrate the significant impact of the Foot & Ankle International in the scientific community of foot and ankle. The current study found a 66.62-fold increase in the number of foot and ankle documents during the period 1980-2019. This may be an important turning point in the field of foot and ankle. The steep increase in the number of documents suggests notable progress in foot and ankle research in terms of scientometric theory. [3][4][5][6][7][8] This indicates that global research on foot and ankle has thrived rapidly over the past four decades, particularly in the last 10 years. In addition, there were five foot and ankle journals in the Journal Citation Reports. The number of subspecialty journals may be higher than those of other subspecialties in orthopedics. These findings reflect the increasing concerns of scientific and medical committees regarding foot and ankle topics. The United States ranked first in terms of research output. This demonstrates the significant potential of the United States in scientific research. This might be due to the large number of high-level researchers and doctors, sufficient funding resources, and good medical policy. 4,6,8,24 Yaohong Wu et al. The United States was not only the most productive county for foot and ankle, but also had the highest h-index. This indicates that the United States made the greatest contribution to the quantity and quality of documents on foot and ankle research. The fact that research productivity differ in different countries may reveal different countries' capabilities in science and technology. 3,4,6,8,[25][26][27][28] This scientometric analysis showed that more than 50% of documents published by authors from the United States, and nearly 90% of global foot and ankle documents were contributed by the top 10 countries. In addition, most of the top 10 countries were developed countries.
These results indicate that global research on foot and ankle was central. The phenomenon of a few countries contributing to a relatively large number of documents was also found in similar scientometric studies. 4,6,8 This may be associated with the comprehensive potential of scientific research in each country, especially the development of education and economy. 4,6,8,23 The majority of the top 10 institutions were located in the United States, which was led by the Hospital for Special Surgery. These institutions produce a great research output for the United States.
However, the Union Memorial Hospital had the highest h-index. This may indicate that the documents from the Union Memorial Hospital are of relatively higher quality than those from other institutions. In addition, the list of the top 10 authors showed authors with good records in foot and ankle research worldwide. 3,4,8,22 These results show the great influence of these institutions and authors. Their contributions play an important role in the development of foot and ankle research. 4,8 The top10 cited documents have been used to analyze hot spots and trends in foot and ankle research over the past four decades.
We found that the majority of documents discussed the rating system or outcome score. The top one documents had far more citations than any other documents. This may indicate that such a document is important for foot and ankle research, and has attracted increasing attention from other studies. Moreover, Foot & Ankle International published 7 of 10 top cited documents, which is considerably more than other foot and ankle journals. One possible reason for this might be that this journal was established earlier than the other journals. It is relatively easy for important documents published earlier to receive more citations. 4,8,23 Another reason may be that this journal attracts more highquality works than other journals. 3,6,8 Limitation: The study has a few limitations, similar to those of previous scientometric analysis. [3][4][5][6][7][8] Not all foot and ankle research has been reported in subspecialty foot and ankle journals. Other journals have also published foot and ankle documents. These journals could not be analyzed in the current study. Moreover, the number of journals included in this study was small. However, these journals present the main publications that have contributed to the field of foot and ankle surgery. Although Scopus is considered an excellent database for scientometric studies, false-negative and false-positive results remain unavoidable. Research activities on certain topics may have been under-or overestimated.

CONCLUSION
Foot and ankle documents have dramatically increase over the past four decades, particularly in the last decade. The United States contributed the greatest number of documents, and had the highest quality of publications. The findings of this study could serve as baseline data for future comparative studies.

Declaration of conflicting interest:
The authors declare that there is no conflict of interest.

Source of funding:
This work was supported by the National Natural Science Foundation of China (81960407).