Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

• Published in: European radiology 2015-06, Vol.25 (6), p.1731-1741
• Main Authors: Horng, Annie, Raya, J. G., Stockinger, M., Notohamiprodjo, M., Pietschmann, M., Hoehne-Hueckstaedt, U., Glitsch, U., Ellegast, R., Hering, K. G., Glaser, C.
• Format: Article
• Language: English
• Subjects: Adult; Arthritis; Bone surgery; Cartilage; Cartilage, Articular - physiology; Deformation; Diagnostic Radiology; Exercise - physiology; Female; Femur - physiology; Hospitals; Humans; Imaging; Imaging, Three-Dimensional; Internal Medicine; Interventional Radiology; Knee; Knee Joint - physiology; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medicine; Medicine & Public Health; Middle Aged; Musculoskeletal; Musculoskeletal system; Neuroradiology; Osteoarthritis; Osteoarthritis, Knee - diagnosis; Osteoarthritis, Knee - physiopathology; Patella - physiology; Posture; Radiology; Range of Motion, Articular - physiology; Tibia - physiology; Topography; Ultrasound; Volunteers; Weight-Bearing - physiology
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-014-3545-7

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