The present study is a cross-sectional observation study. Following metrics were analyzed from the journal's homepage (http://www.ecios.org) and Web of Science Core Collection: number of citable and noncitable articles, number of original articles supported by grants, editorial board members' countries, authors' countries, citing authors' countries, source titles of citing articles, impact factor, total citations, comparison of impact factor with that of 3 Science Citation Index Expanded (SCIE) journals (Acta Orthopaedica et Traumatologica Turcica from Turkey, Indian Journal of Orthopaedics from India, and Journal of Orthopaedic Science from Japan), and Hirsch index (H-index). Publication types of citable articles are review articles, original articles, brief reports, and case reports. The impact factor of a journal for a given year was calculated by below formula:

The H-index was defined as the number of papers with a citation number higher or equal to h. A scientist has index h if his or her Np (number of published) papers have at least h citations each and the other (Np-h) papers have < h citations each.1)

Data retrieval and analysis were done on January 28, 2016.

There was a steady increase in the number of articles published in CiOS from 40 in 2009 to 84 in 2015. Accordingly, the number of citable articles has also grown during the same period: 378 (96.4%) of the total 392 articles were citable articles (Fig. 1). Of the total 282 original articles, 52 (18.4%) were supported by research grants. The proportion of funded research has fluctuated during the period: 9.4% in 2010 as opposed to 25.0% in 2014 (Fig. 2). The editorial board consists of 61 specialists in their respective fields from 13 different countries: 25 from Korea, 13 from USA, 11 from Japan, and 12 from 10 other countries (Fig. 3). Authors of CiOS were from 20 countries: most of the authors were Korean (319, 81.4%), followed by American (22, 5.6%), Japanese (13, 3.3%), and Indian (12, 3.1%) (Fig. 4).

Of the 392 articles published between 2009 and 2015, 263 (67.1%) were cited at least once by articles in the Web of Science Core Collection database. The number of countries of citing authors was 66. The largest number of citing authors was in the USA (321), followed by Korea (170), and China (132) (Fig. 5). The number of journals that published articles citing CiOS publications was more than 100. In particular, the top ranking 7 journals that frequently cited CiOS were Knee Surgery Sports Traumatology Arthroscopy (46), Arthroscopy the Journal of Arthroscopic and Related Surgery (33), American Journal of Sports Medicine (30), International Orthopedics (27), Journal of Hand Surgery American Volume (26), Journal of Arthroplasty (26), and Clinical Orthopedics and Related Research (26). The total citations of CiOS have increased from 0 in 2009 to 374 in 2015 (Fig. 6). The impact factor without journal self-citations was compared with that of 3 SCIE journals from Asia: Acta Orthopaedica et Traumatologica Turcica from Turkey, Indian Journal of Orthopaedics from India, and Journal of Orthopaedic Science from Japan. The impact factor excluding self-citations was the greatest for CiOS among the 4 Asian journals in 2013 and 2014 (Fig. 7). In addition, the impact factor of 1.10 in 2013 corresponded to the percentile rank of 59.7% (40th of the 67 journals related to orthopedic surgery) and 0.94 in 2014 corresponded to the percentile rank of 61.1% (44th of 72 journals in the same field). The 2015 impact factor was calculated as 0.79 in January 2016.

Thirty-seven articles had been cited at least 10 times each. Fifteen articles had been cited at least 13 times each by Web of Science Core Collection journals; therefore, the H-index was 13 (Table 1). The publication types of the most frequently cited 15 articles were original article (14) and review article (1).

Publication of 84 articles, the impact factor of 0.79, the total citations of 374, and the H-index of 13 are the evidence of dramatic evolution of CiOS in 2015 into an internationally recognized journal. In addition, the editorial board includes 13 members outside the country, and authors from 20 different countries have contributed their works to the journal. Although the definition of an international journal has yet to be determined, it seems reasonable to use the following features as criteria: editorial board members from a variety of countries; contributing authors from various countries; worldwide circulation and citations; and inclusion in international indexing databases. From this standpoint, CiOS seems to deserve high recognition from the international community.

The above-described journal metrics were comparable to those of other medical journals published in Korea. The proportion of funded original articles (18.4%) was comparable to the following journals (Fig. 2): Diabetes & Metabolism Journal, 43.9%;2) Clinical and Experimental Reproductive Medicine, 39.8%;3) International Neurourology Journal, 38.6%;4) Clinical Endoscopy, 38.2%;5) Annals of Rehabilitation Medicine, 34.2%;6) Neurointervention 29.0%;7) and Journal of Educational Evaluation for Health Professions, 29.0%.8) The proportion of funded articles is important in that it can inform researchers of important current topics not only in the academic society but also in a specific country and researchers can learn about the development trends in specific fields based on the observation of funding sources and frequent research topics. In addition, it is often difficult to obtain research funding in the surgical clinical field; therefore, the proportion of 18.4% cannot be underestimated.

Currently, the editorial board members of CiOS are from 13 different countries; there should be additional recruitment from more than 20 countries to promote submission of manuscripts from all over the world (Fig. 3). To this end, the editors and board members should contact orthopedic surgeons in their network. Especially, more board members should be recruited from Africa and Latin America to widen the author and reviewer pool. A predominantly large number of articles (366 out of 392, 91.8%) were submitted only by authors from Korea, USA, Japan, and India, which can be overcome by recruiting new editorial board members from a variety of countries (Fig. 4). Citation of articles by researchers from 66 different countries can be considered an indication that the journal has strived to fulfill the aim of promoting communication regarding orthopedic problems and advanced patient care (Fig. 5). The higher frequency of citation by articles published in USA, Korea, and China also reflects a trend in research production in the world. USA and China are the two top countries in terms of the number of publication of research articles. Frequent citation by Korean researchers can be construed as showing that the results of the articles were especially useful for Korean orthopedic surgeons. Considering that most frequently citing journals were all top-notch orthopedic journals, it can be assumed that CiOS has already attained a central position in the network of prestigious orthopedic journals (Fig. 6). The total citations of CiOS articles have been soaring since it was accepted for indexing in PubMed Central/PubMed in November 2009. The journal began to be exposed to the world researchers and physicians through PubMed Central/PubMed, which resulted in more than 300 citations. Therefore, it is not an overstatement that PubMed Central is the most important platform for local English journals to become leading international journals.9)

Impact factor reflects the influence of a journal as a medium for communication or development in a certain scientific field. In 2015, the median impact factor of orthopedic journals was 1.490 and the aggregate impact factor was 2.079. Hence, the 2015 impact factor of 0.79 of CiOS can be considered relatively good. The impact factor without self-citations of CiOS was compared with that of 3 Asian orthopedic journals indexed in Journal Citation Reports, which showed that CiOS attained the highest impact factor among the groups (Fig. 7). Therefore, based on journal metrics, CiOS can be considered the most valuable journal at least among the orthopedic journals published in Asia.

With regard to the H-index, CiOS obtained an excellent score of 13 compared to that of other medical journals published in Korea: the value was 7 for 80 citable articles of Neurointervention;7) 5 for 141 citable articles of Journal of Educational Evaluation for Health Professions;8) 11 for 930 articles of Korean Journal of Urology;10) 6 for 352 articles of Archives of Plastic Surgery;11) and 15 for 1,305 articles of Korean Journal of Internal Medicine.12) Considering that 37 articles have been cited at least 10 times each, it can be expected that the H-index score would increase rapidly in the future. Among the 15 highly cited articles, the publication type of 14 articles was original article, which was comparable to other journals: twelve out of 15 highly cited articles were original articles in case of Korean Journal of Urology.10)

For achievement of such excellent bibliometric status, introduction of a variety of digital publication standards for scholarly journals was essential. Journal Article Tag Suite (JATS) XML, formerly known as PubMed Central (PMC) XML, is a basic digital production form.1314) Since JATS XML is required to be deposited in PMC, it would not have been possible for CiOS to make its international presence without JATS XML. Digital Object Identifier was also crucial in constructing the journal network with reference hyperlink and cited-by functions. CrossMark and FundRef were new services on the articles' recentness and funder identification (ID).15) There are further digital standards that need to be incorporated into the journal: Open Researcher and Contributor ID (ORCID),16) QR code,17) CrossRef Text and Data Mining,18) and audio or video presentation of articles.19) ORCID was introduced as a standard researcher identification solution in October 2012. QR codes are convenient for smartphone users to have access to articles rapidly by taking pictures of codes. CrossRef Text and Data Mining service is a convenient platform for meta-analyses or systemic reviews. Audio or video presentation tends to pique the interest of readers or users to the contents.

Who should be accredited for the success of CiOS as an international journal? At first, Dr. Moon Sang Chung, the founding editor-in-chief, and Dr. Choon-Ki Lee, the second editor-in-chief, should be appreciated for their commitment and dedication. Also, Dr. Shin-Yoon Kim, the incumbent editor-in-chief, has tirelessly devoted himself to development of the journal. The editorial board members' laborious contribution and the KOA's financial support were also instrumental in the evolution of CiOS into a top-notch journal. I believe CiOS will become one of the most influential journals in the orthopedic field in the future considering the continued efforts to serve as a vehicle for communication of valuable information for orthopedic surgeons and patients and their families.