title: The Rising Incidence of Degenerative and Posttraumatic Osteoarthritis of the Knee in the United States Military.
abstract: This investigation sought to quantify incidence rates (IRs) and risk factors for primary and secondary (ie, posttraumatic) osteoarthritis (OA) of the knee in an active military population.
  
  
  
  We performed a retrospective review of United States military active duty servicemembers with first-time diagnosis of primary (International Classification of Disease, 9th Edition code: 715.16) and secondary (International Classification of Disease, 9th Edition code: 715.26) OA of the knee between 2005 and 2014 using the Defense Medical Epidemiology Database. IRs and 95% CIs were expressed per 1000 person-years, with stratified subgroup analysis adjusted for sex, age, race, military rank, and branch of military service. Relative risk factors were evaluated using IR ratios and multiple regression analysis.
  
  
  
  A total of 21,318 cases of OA of the knee were identified among an at-risk population of 13,820,906 person-years for an overall IR of 1.54 per 1000 person-years, including 19,504 cases of primary (IR: 1.41) and 1814 cases of secondary OA (IR: 0.13). The IRs of both primary and secondary OA increased significantly from 2005 to 2014. Increasing age (P < .0001); black race (P < .001); senior military rank (P < .0001); and Army, Marines, and Air Force services (P < .0001) were significantly associated with an increased risk for knee OA.
  
  
  
  This study is the first large-scale report of knee OA in a young athletic population. An increasing incidence and several risk factors for knee OA were identified, indicating a need for better preventative strategies and forecasting the increased anticipated demands for knee arthroplasty among US military servicemembers.
authors.affiliation: Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas.
authors.forename: James E
authors.initials: JE
authors.lastname: Showery
authors.affiliation: Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Kusnezov
authors.affiliation: Department of Orthopaedic Surgery and Rehabilitation, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: John C
authors.initials: JC
authors.lastname: Dunn
authors.affiliation: Department of Clinical Investigation, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: Julia O
authors.initials: JO
authors.lastname: Bader
authors.affiliation: Department of Clinical Investigation, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Belmont
authors.affiliation: Department of Clinical Investigation, William Beaumont Army Medical Center, El Paso, Texas.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Waterman
mesh_terms: D000328:Adult; D016208:Databases, Factual; D005260:Female; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D007718:Knee Injuries / Q000150:complications*; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data*; D015999:Multivariate Analysis; D020370:Osteoarthritis, Knee / Q000453:epidemiology* / Q000209:etiology; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: arthritis; epidemiology; knee; military; post-traumatic