title: American Society of Biomechanics Clinical Biomechanics Award 2015: MRI assessments of cartilage mechanics, morphology and composition following reconstruction of the anterior cruciate ligament.
abstract: The pathogenesis of osteoarthritis following anterior cruciate ligament (ACL) reconstruction is currently unknown. The study purpose was to leverage recent advances in quantitative and dynamic MRI to test the hypothesis that abnormal joint mechanics within four years of reconstruction is accompanied by evidence of early compositional changes in cartilage.
  
  
  
  Static MR imaging was performed bilaterally on eleven subjects with an ACL reconstruction (1-4years post-surgery) and on twelve healthy subjects to obtain tibial cartilage thickness maps. Quantitative imaging (mcDESPOT) was performed unilaterally on all subjects to assess the fraction of bound water in the tibial plateau cartilage. Finally, volumetric dynamic imaging was performed to assess cartilage contact patterns during an active knee flexion-extension task. A repeated-measures ANOVA was used to test for the effects of surgical reconstruction and location on cartilage thickness, bound water fractions, and contact across the medial and lateral tibia plateaus.
  
  
  
  No significant differences in cartilage thickness were found between groups. However, there was a significant reduction in the fraction of water bound by proteoglycan in the ACL reconstructed knees, most notably along the anterior portion of the medial plateau and the weight-bearing lateral plateau. During movement, reconstructed knees exhibited greater contact along the medial spine in the medial plateau and along the posterior aspect of the lateral plateau, when compared with their healthy contralateral knees and healthy controls.
  
  
  
  This study provides evidence that abnormal mechanics in anterior cruciate ligament reconstructed knees are present coincidently with early biomarkers of cartilage degeneration.
authors.affiliation: Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Avenue, Madison, WI 53706, USA.
authors.forename: Jarred
authors.initials: J
authors.lastname: Kaiser
authors.affiliation: Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Avenue, Madison, WI 53706, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Vignos
authors.affiliation: Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, WI 53705, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Radiology, University of Wisconsin - Madison, 600 Highland Avenue, Madison, WI 537924, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Kijowski
authors.affiliation: Department of Mechanical Engineering, University of Wisconsin-Madison, 1513 University Avenue, Madison, WI 53706, USA; Department of Biomedical Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA; Department of Orthopedics and Rehabilitation, University of Wisconsin - Madison, 1685 Highland Avenue, Madison, WI 53705, USA. Electronic address: dgthelen@wisc.edu.
authors.forename: Darryl G
authors.initials: DG
authors.lastname: Thelen
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction; D002358:Cartilage, Articular / Q000473:pathology* / Q000502:physiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D016474:Weight-Bearing; D055815:Young Adult
keywords: Anterior cruciate ligament reconstruction; Biomarkers; Biomechanics; Cartilage; Dynamic MRI; Thickness