title: Changes to the articular cartilage thickness profile of the tibia following anterior cruciate ligament injury.
abstract: OBJECTIVE
  We sought to determine if anterior cruciate ligament (ACL)-injured subjects demonstrated side-to-side differences in tibial cartilage thickness soon after injury, and if uninjured-control subjects displayed side-to-side symmetry in cartilage thickness. Second, we aimed to investigate associations between body mass index (BMI), cross-sectional area (CSA) of the proximal tibia, and articular cartilage thickness differences.
  
  
  METHODS
  Bilateral Magnetic Resonance Images (MRIs) were obtained on 88 ACL-injured subjects (27 male; 61 female) a mean 27 days post-injury, and 88 matched uninjured control subjects. Within ACL-injured and uninjured control subjects, side-to-side differences in medial and lateral tibial articular cartilage thickness were analyzed with adjustment for tibial position relative to the femur during MRI acquisition. Associations between tibial CSA and cartilage thickness differences were tested within high and low BMI groups.
  
  
  RESULTS
  Within the medial tibial compartment, ACL-injured females displayed significant increases: mean (confidence interval (CI)) = +0.18 mm (0.17, 0.19) and decreases: mean (CI) = -0.14 mm (-0.13, -0.15) in tibial cartilage thickness within the central and posterior cartilage regions respectively. Adjustment for tibial position revealed a decreased area of significant cartilage thickness differences, though 46% of points maintained significance. In the lateral compartment anterior region, there was a significantly different relationship between cartilage thickness differences and CSA, within high and low BMI groups (BMI group*CSA interaction, P = 0.007). Within the low BMI group, a significant negative correlation between cartilage thickness and CSA was identified (P = 0.03).
  
  
  CONCLUSIONS
  ACL-injured females displayed cartilage thickness differences in the central, and posterior medial tibial cartilage regions. Tibial position effected thickness differences, but did not account for all significant differences.
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT, USA. Electronic address: Erin.Argentieri@uvm.edu.
authors.forename: E C
authors.initials: EC
authors.lastname: Argentieri
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT, USA. Electronic address: Daniel.Sturnick@uvm.edu.
authors.forename: D R
authors.initials: DR
authors.lastname: Sturnick
authors.affiliation: Department of Medical Biostatistics, University of Vermont, Burlington, VT, USA. Electronic address: Michael.DeSarno@uvm.edu.
authors.forename: M J
authors.initials: MJ
authors.lastname: DeSarno
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT, USA. Electronic address: Mack.Gardner-Morse@uvm.edu.
authors.forename: M G
authors.initials: MG
authors.lastname: Gardner-Morse
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT, USA. Electronic address: James.Slauterbeck@uvm.edu.
authors.forename: J R
authors.initials: JR
authors.lastname: Slauterbeck
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT, USA. Electronic address: Robert.Johnson@uvm.edu.
authors.forename: R J
authors.initials: RJ
authors.lastname: Johnson
authors.affiliation: Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington, VT, USA. Electronic address: Bruce.Beynnon@uvm.edu.
authors.forename: B D
authors.initials: BD
authors.lastname: Beynnon
mesh_terms: D000293:Adolescent; D000070598:Anterior Cruciate Ligament Injuries; D015992:Body Mass Index; D002358:Cartilage, Articular / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000473:pathology*; D007719:Knee Joint / Q000473:pathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D011446:Prospective Studies; D012737:Sex Factors; D013977:Tibia / Q000473:pathology*; D055815:Young Adult
keywords: ACL injury; Cartilage morphology; Cartilage thickness; Joint trauma; PTOA; Tibia