title: The effect of anterior cruciate ligament graft rotation on knee biomechanics.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects on knee biomechanics of rotating the distal end of the bone-patellar tendon graft 90° in anatomic single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with a porcine model.
  
  
  METHODS
  Twenty (n = 20) porcine knees were evaluated using a robotic testing system. Two groups and three knee states were compared: (1) intact ACL, (2) deficient ACL and (3) anatomic SB ACL reconstruction with (a) non-rotated graft or (b) rotated graft (anatomic external fibre rotation). Anterior tibial translation (ATT), internal (IR) and external rotation (ER) and the in situ tissue force were measured under an 89-N anterior tibial (AT) load and 4-N m internal and external tibial torques.
  
  
  RESULTS
  A significant difference from the intact ACL was found in ATT at 60° and 90° of knee flexion for rotated and non-rotated graft reconstructions (p < 0.05). There was a significant difference in the in situ force from the intact ACL with AT loading for rotated and non-rotated graft reconstructions at 60° and 90° of knee flexion (p < 0.05). Under IR loading, the in situ force was significantly different from the intact ACL at 30° and 60° of knee flexion for rotated and non-rotated graft reconstructions (p < 0.05). There were no significant differences in ATT, IR, ER and the in situ force between rotated and non-rotated reconstructions.
  
  
  CONCLUSIONS
  Graft rotation can be used with anatomic SB ACL reconstruction and not have a deleterious effect on knee anterior and rotational biomechanics. This study has clinical relevance in regard to the use of graft rotation to better reproduce the native ACL fibre orientation in ACL reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.
authors.forename: Levent
authors.initials: L
authors.lastname: Surer
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Michail
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.
authors.forename: Murat
authors.initials: M
authors.lastname: Koken
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.
authors.forename: Can
authors.initials: C
authors.lastname: Yapici
authors.affiliation: Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Junjun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Brandon D
authors.initials: BD
authors.lastname: Marshall
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.
authors.forename: Monica A
authors.initials: MA
authors.lastname: Linde
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA.|Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Smolinski
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, 1010 Kaufmann Building, Pittsburgh, PA, 15213, USA. ffu@upmc.edu.|Department of Mechanical Engineering and Material Science, University of Pittsburgh, Pittsburgh, PA, USA. ffu@upmc.edu.
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
mesh_terms: D000818:Animals; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy; D001696:Biomechanical Phenomena / Q000502:physiology; D050376:Bone-Patellar Tendon-Bone Grafting / Q000379:methods*; D012399:Rotation; D013264:Stifle / Q000502:physiology*; D013552:Swine
keywords: ACL reconstruction; Graft rotation; Porcine