title: Inferior results after revision ACL reconstructions: a comparison with primary ACL reconstructions.
abstract: OBJECTIVE
  Anterior cruciate ligament (ACL) ruptures are common, especially among young athletes, and such injuries may have considerable impact on both sport careers and everyday life. ACL reconstructions are successful for most patients, but some suffer from persistent giving-way symptoms and/or re-ruptures requiring revision surgery. The aim of this study was to evaluate the results after revision ACL reconstructions and compare them with the results in a control group consisting of primary ACL reconstructions.
  
  
  METHODS
  This retrospective study included 56 patients undergoing revision ACL reconstruction and 52 patients receiving primary ACL reconstructions. The follow-up evaluation included clinical examination, instrumented laxity testing, testing of muscle strength, Tegner activity score, Lysholm score, Knee injury and osteoarthritis outcome score (KOOS) and radiological grading of osteoarthritis.
  
  
  RESULTS
  The median time from the last ACL reconstruction to follow-up was 90 months in the revision ACL reconstruction group and 96 months in the primary ACL reconstruction group. The revision group had significantly inferior KOOS and Lysholm scores compared with the primary group. Patients in the revision group also showed greater laxity measured with the pivot shift test, a larger reduction in the Tegner activity score, reduced muscle strength in the injured knee, and more severe radiological osteoarthritis; however, no difference in anterior-posterior translation was found.
  
  
  CONCLUSIONS
  Inferior results were found on several of the testing parameters in the revision group compared with the primary group. Patients should receive this information prior to revision ACL reconstructions.
  
  
  METHODS
  III.
authors.affiliation: Orthopaedic Research Center, Trondheim University Hospital, 7006, Trondheim, Norway. tone.gifstad@ntnu.no
authors.forename: Tone
authors.initials: T
authors.lastname: Gifstad
authors.forename: Jon Olav
authors.initials: JO
authors.lastname: Drogset
authors.forename: Annja
authors.initials: A
authors.lastname: Viset
authors.forename: Torbjørn
authors.initials: T
authors.lastname: Grøntvedt
authors.forename: Grete Sofie
authors.initials: GS
authors.lastname: Hortemo
mesh_terms: D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult