title: Clavicle fractures in the United States military: incidence and characteristics.
abstract: BACKGROUND
  Although it is generally known that clavicle fractures represent a common injury of the shoulder girdle in the general population, the true incidence in the active duty military population is unknown. Given the implications for such injuries on the ability to perform occupation-specific tasks, determining the incidence in the U.S. military population is worthwhile. The purpose of this study was to determine the incidence of clavicle fractures in the U.S. military and to identify any demographic risk factors for injury.
  
  
  METHODS
  We performed a query of the Defense Medical Epidemiology Database with the code from the International Classification of Diseases, Ninth Revision, for clavicle fractures for the years 1999 through 2008. An overall injury incidence was calculated, in addition to multivariate analysis, to determine independent risk factors among the following demographic considerations: sex, race, branch of military service, rank, and age.
  
  
  RESULTS
  During the study period, a total of 12,514 clavicle fractures were documented among an at-risk population of 13,770,767 person-years for an incidence rate (IR) of 0.91 per 1,000 person-years in the U.S. Military. Males, when compared with females, were more than twice as likely to sustain a clavicle fracture (IR ratios [IRR], 2.30; 95% confidence intervals [CI], 2.12-2.49). The peak incidence of clavicle fractures occurred in the age groups of <20 and 20 to 24. Compared to black service members, the white service members were associated with significantly higher rate of clavicle fractures (IRR, 2.45; 95% CI, 2.28-2.63). The service members serving in the Marine Corps were associated with a higher IR of clavicle fractures when compared to those in the Navy (IRR, 1.44; 95% CI, 1.35-1.53). Junior enlisted service members were 34% as likely to sustain a clavicle fracture when compared to senior officers (IRR, 1.46; 95% CI, 1.34-1.60 and IRR, 1.12; 95% CI, 0.99-1.28, respectively).
  
  
  CONCLUSIONS
  The incidence of clavicle fractures among U.S. military personnel (0.908 per 1,000 person-years) is higher than previous epidemiological reports.
authors.affiliation: Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, 5005 North Piedras Street, RM 3C49, El Paso, TX 79920-5001, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hsiao
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Cameron
authors.forename: Jeannie
authors.initials: J
authors.lastname: Huh
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Hsu
authors.forename: Matthew
authors.initials: M
authors.lastname: Benigni
authors.forename: JoAnna C
authors.initials: JC
authors.lastname: Whitener
authors.forename: Brett D
authors.initials: BD
authors.lastname: Owens
mesh_terms: D000328:Adult; D044383:Black People / Q000706:statistics & numerical data; D002968:Clavicle / Q000293:injuries*; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D017678:Sex Distribution; D014481:United States; D044465:White People / Q000706:statistics & numerical data; D055815:Young Adult; D001741:Black or African American