title: Incidence and outcomes of anterior cruciate ligament reconstruction among U.S. Army aviators.
abstract: BACKGROUND
  The incidence, injury history and aeromedical disposition of anterior cruciate ligament (ACL) reconstruction among Army aviators is unknown.
  
  
  METHODS
  The U.S. Army Aviation Epidemiology Data Register was queried for the study period of calendar years 1988-95. Factors considered included age, gender, type and mechanism of injury, prior history of ACL reconstruction, and final aeromedical disposition. The population was divided into two groups: Group I aviators had no history of ACL injury before entering aviation service, while Group II aviators had ACL reconstructions prior to entering aviation service. The data set was analyzed to determine the incidence of ACL reconstruction, to characterize the type and mechanism of injury and to determine the risk of aeromedical termination from service.
  
  
  RESULTS
  The ACL reconstruction rate (ACL reconstructions/1000 aviators per year) was 0.52 overall, 0.50 for males and 1.39 for females. Sports accounted for 76% of the injuries requiring ACL reconstruction. The ACL reconstruction rate in Group I was 0.050%, while that of Group II was 63.3%. Among Group I aviators requiring ACL reconstruction, 94.3% returned to aviation service, 2.3% were aeromedically terminated and 3.4% were lost to follow-up. Among Group II aviators requiring revision ACL reconstruction, 60% returned to aviation service and 40% were aeromedically terminated.
  
  
  CONCLUSIONS
  Female aviators and Group II aviators had the greatest risk of requiring ACL surgery. Group II aviators had a greater likelihood of undergoing a revision ACL reconstruction and subsequent aeromedical termination compared with an initial ACL reconstruction for Group I aviators.
authors.affiliation: Department of Aviation Medicine, Lyster Army Community Hospital, Ft. Rucker, AL, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Belmont
authors.forename: S B
authors.initials: SB
authors.lastname: Shawen
authors.forename: K T
authors.initials: KT
authors.lastname: Mason
authors.forename: S J
authors.initials: SJ
authors.lastname: Sladicka
mesh_terms: D000293:Adolescent; D000328:Adult; D000337:Aerospace Medicine; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008889:Military Personnel; D012086:Reoperation / Q000706:statistics & numerical data; D012307:Risk Factors; D017678:Sex Distribution; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014947:Wounds and Injuries / Q000453:epidemiology