Knee Cartilage Thickness, T1ρ and T2 Relaxation Time Are Related to Articular Cartilage Loading in Healthy Adults

• Published in: PloS one Vol. 12; no. 1; p. e0170002
• Main Authors: Van Rossom, Sam, Smith, Colin Robert, Zevenbergen, Lianne, Thelen, Darryl Gerard, Vanwanseele, Benedicte, Van Assche, Dieter, Jonkers, Ilse
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.01.2017; Public Library of Science (PLoS)
• Subjects: Adult; Adults; Arthritis; Biochemical composition; Biology and Life Sciences; Biomechanical Phenomena - physiology; Biomechanics; Cartilage; Cartilage (articular); Cartilage, Articular - anatomy & histology; Cartilage, Articular - diagnostic imaging; Cartilage, Articular - physiology; Collagen; Contact force; Contact pressure; Correlation; Data acquisition; Female; Femur; Gait; Healthy Volunteers; Humans; Impulses; Joint surgery; Kinesiology; Knee; Knee Joint - anatomy & histology; Knee Joint - diagnostic imaging; Knee Joint - physiology; Magnetic resonance imaging; Male; Mechanical engineering; Medicine and Health Sciences; Muscle Relaxation - physiology; NMR; Nuclear magnetic resonance; Organ Size; Physical Sciences; Pressure; Pressure distribution; Range of Motion, Articular; Rehabilitation; Relaxation time; Skin & tissue grafts; Stress analysis; Stress concentration; Time compression; Walking; Weight-Bearing - physiology; Young Adult
• DOI: 10.1371/journal.pone.0170002
• ISSN: 1932-6203

Cartilage is responsive to the loading imposed during cyclic routine activities. However, the local relation between cartilage in terms of thickness distribution and biochemical composition and the local contact pressure during walking has not been established. The objective of this study was to evaluate the relation between cartilage thickness, proteoglycan and collagen concentration in the knee joint and knee loading in terms of contact forces and pressure during walking. 3D gait analysis and MRI (3D-FSE, T1ρ relaxation time and T2 relaxation time sequence) of fifteen healthy subjects were acquired. Experimental gait data was processed using musculoskeletal modeling to calculate the contact forces, impulses and pressure distribution in the tibiofemoral joint. Correlates to local cartilage thickness and mean T1ρ and T2 relaxation times of the weight-bearing area of the femoral condyles were examined. Local thickness was significantly correlated with local pressure: medial thickness was correlated with medial condyle contact pressure and contact force, and lateral condyle thickness was correlated with lateral condyle contact pressure and contact force during stance. Furthermore, average T1ρ and T2 relaxation time correlated significantly with the peak contact forces and impulses. Increased T1ρ relaxation time correlated with increased shear loading, decreased T1ρ and T2 relaxation time correlated with increased compressive forces and pressures. Thicker cartilage was correlated with higher condylar loading during walking, suggesting that cartilage thickness is increased in those areas experiencing higher loading during a cyclic activity such as gait. Furthermore, the proteoglycan and collagen concentration and orientation derived from T1ρ and T2 relaxation measures were related to loading.