title: Incidence and risk factors associated with meniscal injuries among active-duty US military service members.
abstract: BACKGROUND
  Few population-based studies have examined the incidence of meniscal injuries, and limited information is available on the influence of patient's demographic and occupational factors.
  
  
  OBJECTIVE
  To examine the incidence of meniscal injuries and the influence of demographic and occupational factors among active-duty US service members between 1998 and 2006.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Using the International Classification of Diseases (9th revision) codes 836.0 (medial meniscus), 836.1 (lateral meniscus), and 836.2 (meniscus unspecified), we extracted injury data from the Defense Medical Surveillance System to identify all acute meniscal injuries among active-duty military personnel.
  
  
  METHODS
  Active-duty military personnel serving in all branches of military service during the study period.
  
  
  METHODS
  Incidence rate (IR) per 1000 person-years at risk and crude and adjusted rates by strata for age, sex, race, rank, and service.
  
  
  RESULTS
  During the study period, 100201 acute meniscal injuries and 12115606 person-years at risk for injury were documented. The overall IR was 8.27 (95% confidence interval [CI] = 8.22, 8.32) per 1000 person-years. Main effects were noted for all demographic and occupational variables (P < .001), indicating that age, sex, race, rank, and service were associated with the incidence of meniscal injuries. Men were almost 20% more likely to experience an acute meniscal injury than were women (incidence rate ratio = 1.18, 95% CI = 1.15, 1.20). The rate of meniscal injury increased with age; those older than 40 years of age experienced injuries more than 4 times as often as those under 20 years of age (incidence rate ratio = 4.25, 95% CI=4.08,4.42).
  
  
  CONCLUSIONS
  The incidence of meniscal injury was substantially higher in this study than in previously reported studies. Male sex, increasing age, and service in the Army or Marine Corps were factors associated with meniscal injuries.
authors.affiliation: Department of Orthopedic Surgery, Keller Army Hospital, Department of Mathematical Sciences, West Point, NY, USA.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Jones
authors.forename: Robert
authors.initials: R
authors.lastname: Burks
authors.forename: Brett D
authors.initials: BD
authors.lastname: Owens
authors.forename: Rodney X
authors.initials: RX
authors.lastname: Sturdivant
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Svoboda
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Cameron
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000453:epidemiology*; D007869:Leg Injuries / Q000453:epidemiology*; D008297:Male; D008889:Military Personnel; D012307:Risk Factors; D012737:Sex Factors; D000070600:Tibial Meniscus Injuries; D014481:United States / Q000453:epidemiology