title: Defining the terms acute and chronic in orthopaedic sports injuries: a systematic review.
abstract: BACKGROUND
  Although many authors report on acute injuries and chronic injuries in the orthopaedic literature, the actual terms are seldom explicitly defined.
  
  
  OBJECTIVE
  Much of the literature pertaining to sports injuries that are acute or chronic does not define these terms. It is believed that definitions will provide clarity and specificity in future literature.
  
  
  METHODS
  Systematic review.
  
  
  METHODS
  A systematic review of 116 articles was conducted to determine whether and how the terms acute and chronic were defined as they pertain to several commonly treated conditions: Achilles tendon rupture, distal biceps tendon rupture, pectoralis major tendon rupture, anterior cruciate ligament (ACL) tear, anterior shoulder instability, and acromioclavicular (AC) joint dislocation. Articles were isolated from various databases and search engines by use of keywords to identify relevant literature.
  
  
  RESULTS
  This study determined that the terms acute and chronic for each injury are defined, respectively, as follows: Achilles tendon rupture: <1 week, >4 weeks; distal biceps tendon rupture: <6 weeks, >12 weeks; pectoralis major tendon rupture: <6 weeks, >6 weeks; ACL tear: <6 weeks, >6 months; anterior shoulder instability: <2 weeks, >6 months; AC joint dislocation, <3 weeks, >6 weeks.
  
  
  CONCLUSIONS
  The current literature varies greatly in defining the terms acute and chronic in common sports injuries. The vast majority of authors imply these terms, based on the method of their studies, rather than define them explicitly. Injuries involving tendons showed greater consistency among authors, thus making a definition based on consensus easier to derive. The literature on ACL and shoulder instability in particular showed great variability in defining these terms, likely representing the more complex nature of these injuries and the fact that timing of surgery in the majority of patients does not particularly affect the complexity of the surgical approach and treatment.
  
  
  CONCLUSIONS
  Defining injuries as acute or chronic is clinically relevant in many cases, particularly concerning tendon injuries, where these terms have implications regarding the anatomic pathologic changes and tissue quality, which may necessitate augmentation and alter the initial surgical plan. In cases where these terms are less pertinent to operative treatment considerations, they bring clarity to the discussion of the acuity of the injury (as it pertains to time from insult).
authors.affiliation: James H. Flint, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda, MD 20889-5600. James.H.Flint.mil@health.mil.
authors.forename: James H
authors.initials: JH
authors.lastname: Flint
authors.forename: Alana M
authors.initials: AM
authors.lastname: Wade
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Giuliani
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Rue
mesh_terms: D000208:Acute Disease; D001265:Athletic Injuries / Q000503:physiopathology*; D002908:Chronic Disease; D006801:Humans; D009141:Musculoskeletal System / Q000293:injuries*; D009626:Terminology as Topic
keywords: Achilles tendon; acromioclavicular joint; acute; anterior cruciate ligament; chronic; distal biceps tendon; pectoralis major tendon; shoulder instability