title: Effect of graft fixation sequence on knee joint biomechanics in double-bundle anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  To investigate the effect of graft fixation sequence in double-bundle anterior cruciate ligament (ACL) reconstruction on knee biomechanics.
  
  
  METHODS
  Twelve mature porcine knees underwent double-bundle ACL reconstruction with a randomized fixation order of the two graft bundles. The knees were subjected to external loadings of (1) an 89 N anterior tibial load at 30°, 60° and 90° of knee flexion and (2) 4 N-m internal and external tibial torques at 30° and 60° of knee flexion for ACL intact, deficient and reconstructed states. Knee kinematics and in situ graft forces were measured under the applied loads.
  
  
  RESULTS
  The anterior tibial translation of the two reconstructions was not different from each other but was significantly different from the intact ACL. There was no difference in internal and external rotations between the intact knees and the reconstructions. At lower flexion angles, the graft that was fixed last (whether anteromedial or posterolateral) tended to carry significantly higher in situ load under anterior tibial loading and tibial torques.
  
  
  CONCLUSIONS
  While a difference in knee kinematics may not be observable with different graft fixation sequences, fixation sequence can alter the in situ forces that the grafts bear under knee loading.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.
authors.forename: Dongliang
authors.initials: D
authors.lastname: Shi
authors.forename: Jingbin
authors.initials: J
authors.lastname: Zhou
authors.forename: Can
authors.initials: C
authors.lastname: Yapici
authors.forename: Monica
authors.initials: M
authors.lastname: Linde-Rosen
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy; D001696:Biomechanical Phenomena; D007719:Knee Joint / Q000502:physiology* / Q000601:surgery; D011897:Random Allocation; D016059:Range of Motion, Articular; D012399:Rotation; D013552:Swine; D013710:Tendons / Q000637:transplantation; D013977:Tibia / Q000502:physiology / Q000601:surgery; D019415:Torque; D016474:Weight-Bearing