title: Knee Cartilage Thickness, T1ρ and T2 Relaxation Time Are Related to Articular Cartilage Loading in Healthy Adults.
abstract: 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.
authors.affiliation: Human movement biomechanics research group, Department of kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Sam
authors.initials: S
authors.lastname: Van Rossom
authors.affiliation: Department of mechanical engineering, University of Wisconsin-Madison, Madison, United States of America.
authors.forename: Colin Robert
authors.initials: CR
authors.lastname: Smith
authors.affiliation: Human movement biomechanics research group, Department of kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Lianne
authors.initials: L
authors.lastname: Zevenbergen
authors.affiliation: Department of mechanical engineering, University of Wisconsin-Madison, Madison, United States of America.|Department of biomedical engineering, University of Wisconsin-Madison, Madison, United States of America.|Department of orthopedics and rehabilitation, University of Wisconsin-Madison, Madison, United States of America.
authors.forename: Darryl Gerard
authors.initials: DG
authors.lastname: Thelen
authors.affiliation: Human movement biomechanics research group, Department of kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Vanwanseele
authors.affiliation: Musculoskeletal rehabilitation research group, Department of rehabilitation sciences, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Dieter
authors.initials: D
authors.lastname: Van Assche
authors.affiliation: Human movement biomechanics research group, Department of kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: Jonkers
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology*; D002358:Cartilage, Articular / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology*; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology; D009929:Organ Size; D016059:Range of Motion, Articular; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult