From MRI to anatomical simulation of the hip joint

This paper describes a methodology for the simulation of musculoskeletal disorders. Our clinical study is related to osteoarthritis (OA) of the hip, a pathogenesis possibly due to impingements. These bone collisions lead to abnormal joint mechanics which is characterized by contact pressure and stress distribution upon the joint cartilages. The proposed methodology combines different approaches from modeling to simulation. The simulation is based on patient-specific anatomical models, where acquisition modalities are noninvasive and flexible. Based on static magnetic resonance imaging (MRI) data, a discrete deformable models method is used for modeling the organs of the musculoskeletal system. Femoroacetabular movements are estimated using an optical motion capture system and are validated by a dynamic MRI analysis. To achieve accurate deformations, techniques to generate volumetric meshes are developed based on the medial axis (MA) information. Finally, a computationally efficient fast functional joint model is used to simulate the mechanical behavior of the soft tissues. The goal of such a simulation is to allow the investigation of the relevant contact and cartilages deformation under movement, which can be useful for diagnosis, pre- or post-operative planning and training. This will benefit further developments in surgical techniques and minimally invasive procedures. Copyright © 2008 John Wiley & Sons, Ltd.