title: Worldwide research productivity in the field of spine surgery: a 10-year bibliometric analysis.
abstract: OBJECTIVE
  Bibliometrics is increasingly used to assess the quantity and quality of scientific research output in many research fields worldwide. However, the bibliometric studies in the field of spine surgery are scarce. This study aimed to evaluate the worldwide research productivity in the field of spine surgery using bibliometric methods and to provide an insight into the spine research for surgeons and researchers.
  
  
  METHODS
  Articles published between 2004 and 2013 were retrieved using the Scopus database in 5 spine journals, including Spine, European Spine Journal, The Spine Journal, Journal of Neurosurgery: Spine, and Journal of Spinal Disorders and Techniques. The number of articles, trend of publications, countries' contribution and h-index, authorship, subspecialty, funding source, journal pattern, institutions, and top cited articles were analyzed.
  
  
  RESULTS
  A total of 13,115 publications were identified in the database of Scopus from 2004 to 2013. The time trend of the number of articles showed a significant increase of 1.9-fold between 2004 and 2013 (p = 0.000). The largest number of articles in the field of spine surgery was from United States (39.17%), followed by Japan (10.74%) and China (8.62%). United States also have the highest h-index (106), followed by Canada (60) and United Kingdom (54). China (p = 0.000) and South Korea (p = 0.000) have a significantly increasing trend of contribution proportion to the world spine production over time in years, but h-index was still low (39 and 38, respectively). Spine published the highest number of articles (45.44%), followed by European Spine Journal (21.43%) and Journal of Neurosurgery: Spine (13.32%). The most productive institutions were University of California, San Francisco (1.98%), followed by Thomas Jefferson University (1.61%) and University of Toronto (1.41%).
  
  
  CONCLUSIONS
  There has a rapid increase of scientific research productivity in the field of spine surgery during the past 10 years. United States has special contributions to the body of spine publications. China and South Korea have increasing contributions to the field of spine surgery.
authors.affiliation: Department of Orthopaedics, Fuzhou General Hospital of Nanjing Military Command, No. 156 West Second Ring Road, Fuzhou, 350025, China.
authors.forename: Meiyang
authors.initials: M
authors.lastname: Wei
authors.affiliation: Department of Orthopaedics, Fuzhou General Hospital of Nanjing Military Command, No. 156 West Second Ring Road, Fuzhou, 350025, China.
authors.forename: Wanming
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Orthopaedics, Fuzhou General Hospital of Nanjing Military Command, No. 156 West Second Ring Road, Fuzhou, 350025, China. zhuangyanfengpla@163.com.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zhuang
mesh_terms: D001319:Authorship; D015706:Bibliometrics; D035843:Biomedical Research / Q000706:statistics & numerical data*; D016208:Databases, Factual; D006801:Humans; D019637:Orthopedic Procedures; D013131:Spine / Q000601:surgery*
keywords: Bibliometrics; Research productivity; Spine