| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4050153 | Clinical Biomechanics | 2016 | 7 Pages |
•MRI was used to image cartilage composition and contact in ACL-reconstructed knees.•Reconstructed knees exhibited abnormal contact on the tibia plateau during movement.•There were lower fractions of water bound by proteoglycan in reconstructed knees.•No cartilage thickness difference was found between reconstructed and control knees.•Results consistent with theorized link between mechanics and cartilage degeneration.
BackgroundThe 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.MethodsStatic MR imaging was performed bilaterally on eleven subjects with an ACL reconstruction (1–4 years 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.FindingsNo 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.InterpretationThis study provides evidence that abnormal mechanics in anterior cruciate ligament reconstructed knees are present coincidently with early biomarkers of cartilage degeneration.
