Karupppasamy Subburaj1, Richard B. Souza1,2, Christoph Stehling3, Brad T. Wyman4, Marie-Pierre Hellio Le Graverand-Gastineau4, Thomas M. Link1, Xiaojuan Li1, Sharmila Majumdar1
1Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, CA, United States; 2Department of Physical Therapy & Rehabilitation Science, University of California San Francisco, San Francisco, CA, United States; 3Department of Clinical Radiology, University of Muenster, Mnster, Germany; 4Pfizer, Inc., Groton, CT, United States
The purpose of this study was to assess the relationship between MR relaxation times and biomechanical response of articular cartilage to physiological loading (cartilage-on-cartilage contact area and deformation) in OA subjects and controls. The contact area in the medial compartment was significantly higher in OA subjects than controls. The pooled data show that cartilage deformation in medial compartment was significantly higher than the lateral compartment. The T1ρ and T2 relaxation times, contact area and cartilage deformation in OA subjects were higher than normal subjects. These results suggest that the structural degradation affects the load bearing capacity of the cartilage.