For this study, all physicians were classified as either orthopedic or nonorthopedic. Orthopedic surgeons—the focus of this study—were defined as those who completed residency training in orthopedic surgery. Median number of orthopedic and nonorthopedic surgeons per team was calculated at the high school, collegiate, and professional levels.
After identifying all orthopedic team physicians, we performed additional Internet searches to determine any affiliation between each physician and an applicable academic medical center. Physicians were placed in 1 of 3 different categories based on “level” of academic affiliation. Orthopedists with no identifiable connection to an academic medical center were listed under none. The first 100 search results were studied before this determination was made. Orthopedists with any academic affiliation below the level of full professorship were placed in the category associate/assistant/adjunct professor, which included any physician who was an associate professor, adjunct professor, clinical instructor, or volunteer instructor at an academic medical center. Last, orthopedists listed as full professors were placed in the professor category.
Number of publications written by each orthopedic team physician was then calculated using SciVerse Scopus (scopus.com), a comprehensive abstract and citation database of research literature that offers complete coverage of the Medline and Embase databases.13 Scopus offers a Scopus Author Identifier, which assigns each author in Scopus a unique identification number.14 This number is based on an “algorithm that matches author names based on their affiliation, address, subject area, source title, dates of publication citations, and co-authors.”14 Authors whose names did not appear in Scopus were assumed to have no publications, and this was reported after cross-referencing with Medline to ensure no documents were missed. This study included all publications: original research articles, reviews, letters, and commentaries. Any level of authorship (first, second, etc) was included. All publications were scanned, and duplicate listings were not included. Median number of publications per orthopedic team physician was calculated at the high school, college, and professional levels.
We also determined the h-index for each orthopedic team physician. The h-index is used to measure the impact of the published work of a scholar: “A scientist has index h if h of his/her papers have at least h citations each, and the other papers have no more than h citations each.”15 For example, an h-index of 12 means that, out of an author’s total number of publications, 12 have been cited at least 12 times, and all of his or her other publications have been cited fewer than 12 times. All authors in Scopus are automatically assigned h-indexes, and we collected these numbers.16 Of note, citations for articles published before 1996 are not included in the h-index calculation. Median h-index score per orthopedic team physician was calculated at the high school, college, and professional levels.
Analysis of variance was used to compare continuous data (eg, number of publications per surgeon) across different groups (eg, physicians from respective sports). Chi-square tests were used to detect whole-number differences between groups (eg, difference in number of physicians per team across the various professional sports leagues). Statistical significance was set at P < .05.
Results
We identified 1054 team physicians among the 362 total high schools, colleges, and professional sports teams included in this study. Of the 1054 physicians, 678 (64%) were orthopedic surgeons (Table 1). Seventy-two (60%) of the 120 high schools did not have a team physician, whereas all the colleges and professional teams did. Number of orthopedic surgeons per team was higher at the collegiate level (2.29; range, 0-11) and professional level (2.21; range, 1-9) than at the high school level (1.11; range, 0-24) (Table 1). Median number of nonorthopedic surgeons was highest in professional sports (1.88; range, 0-9) followed by college sports (1.06; range, 0-9) and high school sports (0.16; range, 0-2) (Table 1).
Of the 678 orthopedic team physicians, 298 (44%) were officially affiliated with an academic medical center, either as clinical instructor, associate/adjunct professor, or full professor. Percentage of orthopedists affiliated with an academic medical center was highest in professional sports (173/270, 64%) followed by collegiate sports (98/275, 36%) and high school sports (27/133, 20%) (P < .001, Table 2). Percentage of orthopedists identified as full professors was highest at the professional level (42/270, 16%) followed by the collegiate level (14/275, 5.1%) and the high school level (3/133, 2.3%) (P < .001, Table 2).
We found 12,036 publications written by the 678 orthopedic team physicians included in this study. Median number of publications per orthopedist was significantly higher in professional sports (30.6; range, 0-460) than in collegiate sports (10.7; range, 0-581) and high school sports (6.0; range, 0-220) (P < .001). Number of authors with more than 25 publications was highest at the professional level (82) followed by the collegiate level (27) and the high school level (7) (Table 3). Median number of publications per orthopedist was also higher at the professional level (12) than at the collegiate level (2) and high school level (1). Median h-index was higher among orthopedists in professional sports (7.1; range, 0-50) than at colleges (2.7; range, 0-63) and high schools (1.8; range, 0-32) (P < .001). Median h-index was also significantly higher at the professional level (5) than at the collegiate level (1) and high school level (0).
