title: Knee stability and graft function after anterior cruciate ligament reconstruction: a comparison of a lateral and an anatomical femoral tunnel placement.
abstract: BACKGROUND
  Locations of femoral tunnels for anterior cruciate ligament replacement grafts remain a subject of debate.
  
  
  OBJECTIVE
  A lateral femoral tunnel placed at the insertion of the posterolateral bundle of the anterior cruciate ligament can restore knee function comparably to anatomical femoral tunnel placement.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Ten cadaveric knees were subjected to the following external loading conditions: (1) a 134-N anterior tibial load and (2) combined rotatory loads of 10-N.m valgus and 5-N.m internal tibial torques. Data on resulting knee kinematics and in situ force of the intact anterior cruciate ligament and anterior cruciate ligament graft were collected using a robotic/universal force-moment sensor testing system for (1) intact, (2) anterior cruciate ligament-deficient, (3) anatomical double-bundle reconstructed, and (4) laterally placed single-bundle reconstructed knees.
  
  
  RESULTS
  In response to anterior tibial load, anterior tibial translation and in situ force in the graft were not significantly different between the 2 reconstructions except at high knee flexion. For example, at 90 degrees of knee flexion, anterior tibial translation was 6.1 +/- 2.3 mm for anatomical double-bundle reconstruction and 7.6 +/- 2.6 mm for laterally placed single-bundle reconstruction (P < .05). In response to rotatory loads, there were no significant differences between the 2 reconstruction procedures (4.8 +/- 2.4 mm vs 4.8 +/- 3.0 mm in anterior tibial translation at 15 degrees of knee flexion, P > .05).
  
  
  CONCLUSIONS
  Lateral tunnel placement can restore rotatory and anterior knee stability similarly to an anatomical reconstruction when the knee is near extension. However, the same is not true when the knee is at high flexion angles.
  
  
  CONCLUSIONS
  To reproduce the complex function of the anterior cruciate ligament, reproducing both bundles of the anterior cruciate ligament may be necessary.
authors.affiliation: Musculoskeletal Research Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Wei-Hsiu
authors.initials: WH
authors.lastname: Hsu
authors.forename: Savio L-Y
authors.initials: SL
authors.lastname: Woo
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Van Scyoc
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Takakura
authors.forename: Richard E
authors.initials: RE
authors.lastname: Debski
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000502:physiology / Q000601:surgery*; D001696:Biomechanical Phenomena; D002102:Cadaver; D005269:Femur / Q000601:surgery; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D007719:Knee Joint / Q000502:physiology / Q000601:surgery*; D008875:Middle Aged; D016059:Range of Motion, Articular / Q000502:physiology; D013710:Tendons / Q000637:transplantation*; D013977:Tibia / Q000601:surgery; D019415:Torque; D016474:Weight-Bearing