title: Can joint contact dynamics be restored by anterior cruciate ligament reconstruction?
abstract: BACKGROUND
  Rotational kinematics has become an important consideration after ACL reconstruction because of its possible influence on knee degeneration. However, it remains unknown whether ACL reconstruction can restore both rotational kinematics and normal joint contact patterns, especially during functional activities.
  
  
  OBJECTIVE
  We asked whether knee kinematics (tibial anterior translation and axial rotation) and joint contact mechanics (tibiofemoral sliding distance) would be restored by double-bundle (DB) or single-bundle (SB) reconstruction.
  
  
  METHODS
  We retrospectively studied 17 patients who underwent ACL reconstruction by the SB (n = 7) or DB (n = 10) procedure. We used dynamic stereo x-ray to capture biplane radiographic images of the knee during downhill treadmill running. Tibial anterior translation, axial rotation, and joint sliding distance in the medial and lateral compartments were compared between reconstructed and contralateral knees in both SB and DB groups.
  
  
  RESULTS
  We observed reduced anterior tibial translation and increased knee rotation in the reconstructed knees compared to the contralateral knees in both SB and DB groups. The mean joint sliding distance on the medial compartment was larger in the reconstructed knees than in the contralateral knees for both the SB group (9.5 ± 3.9 mm versus 7.5 ± 4.3 mm) and the DB group (11.1 ± 1.3 mm versus 7.9 ± 3.8 mm).
  
  
  CONCLUSIONS
  Neither ACL reconstruction procedure restored normal knee kinematics or medial joint sliding.
  
  
  CONCLUSIONS
  Further study is necessary to understand the clinical significance of abnormal joint contact, identify the responsible mechanisms, and optimize reconstruction procedures for restoring normal joint mechanics after ACL injury.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, Pittsburgh, PA 15213, USA.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
authors.forename: James J
authors.initials: JJ
authors.lastname: Irrgang
authors.forename: Scott
authors.initials: S
authors.lastname: Tashman
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology / Q000601:surgery*; D007718:Knee Injuries / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology*; D019651:Plastic Surgery Procedures / Q000379:methods; D012189:Retrospective Studies