Published in:
01-06-2015 | Musculoskeletal
Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T
Authors:
Annie Horng, J. G. Raya, M. Stockinger, M. Notohamiprodjo, M. Pietschmann, U. Hoehne-Hueckstaedt, U. Glitsch, R. Ellegast, K. G. Hering, C. Glaser
Published in:
European Radiology
|
Issue 6/2015
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Abstract
Objectives
To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures.
Methods
Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments.
Results
Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals.
Conclusions
Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities.
Key points
• 3D MRI helps differentiate true knee-cartilage deformation from random measurement error
• 3D MRI maps depict in vivo topographic distribution of cartilage deformation after loading
• 3D MRI maps depict in vivo intensity of cartilage deformation after loading
• Locating cartilage contact areas might aid differentiating common and work-related osteoarthritis