Abstract
Biomechanical factors may play a critical role in the initiation and progression of Osteoarthritis (OA). We present a method to quantify the medial tibiofemoral (MTF) congruity from low-field magnetic resonance imaging (MRI). Firstly, the MTF cartilage compartments were segmented fully automatically using a voxel quantification approach. Further, the contact area (CA) was computed using the Euclidian distance transformation by setting the voxel width as threshold. Eventually, the congruity index (CI) was computed point-by-point over CA as the inverse distance between the local normal vectors scaled by the local normal curvatures along the local direction of principal knee motion. The ability of the CI quantification method was cross-validated for various tasks of diagnosis of OA. Healthy knees were more congruent than knees with OA. These quantification methods might be suitable to help explain the onset and diagnosis of OA.
