title: The effect of tunnel placement on rotational stability after ACL reconstruction: evaluation with use of triaxial accelerometry in a porcine model.
abstract: OBJECTIVE
  Conventional transtibial technique fails to restore the rotational knee stability in spite of successful anterior laxity, while anatomic anterior cruciate ligament reconstruction using the anteromedial portal technique has been developed expecting better rotational kinematics because of closer reproduction of the native anterior cruciate ligament anatomy. However, the rotational instability after those two procedures has not been fully examined especially in terms of dynamic component of the rotational stability. The purpose was to assess the effect of anatomic versus non-anatomic tunnel placement on rotational knee stability after anterior cruciate ligament reconstruction using triaxial accelerometry.
  
  
  METHODS
  Sixteen porcine knees underwent a manual pivot-shift test at four different conditions: (1) anterior cruciate ligament intact, (2) anterior cruciate ligament deficient, (3) non-anatomic transtibial reconstruction, and (4) anatomic anteromedial portal reconstruction. The three-dimensional acceleration of knee motion during the pivot-shift test was recorded using a triaxial accelerometer.
  
  
  RESULTS
  Both anterior cruciate ligament reconstructions decreased significantly the acceleration of the pivot-shift test from the increased level in the anterior cruciate ligament-deficient condition. However, the transtibial technique fails to reach the intact level of acceleration, while the anteromedial portal technique reduced the acceleration to even less than the intact level.
  
  
  CONCLUSIONS
  The transtibial anterior cruciate ligament reconstruction could not restore the dynamic rotational stability of the intact knee, whereas the anteromedial portal technique restored the dynamic rotational stability closer to the intact level.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA 15213, USA.
authors.forename: Aníbal
authors.initials: A
authors.lastname: Debandi
authors.forename: Akira
authors.initials: A
authors.lastname: Maeyama
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hoshino
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Asai
authors.forename: Bunsei
authors.initials: B
authors.lastname: Goto
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D061725:Accelerometry; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001696:Biomechanical Phenomena; D005269:Femur / Q000601:surgery*; D007593:Joint Instability / Q000503:physiopathology* / Q000601:surgery; D012399:Rotation; D013552:Swine; D013977:Tibia / Q000601:surgery*