Hip motion analysis using multi phase (virtual and physical) simulation of the patient-specific hip joint dynamics

In total hip arthroplasty (THA), the patient-specific bone geometry or the characteristics of the skeletal movement should be considered during treatment in order to prevent complications. In this paper, we propose a novel approach for the analysis of joints which combines the patient-specific virtual and physical simulation. The patient-specific anatomical structure and hip motion was obtained from CT and optical motion capture. The virtual simulation was conducted by integrating these data using virtual reality technique. The physical simulation was achieved by using plaster models of the patient's pelvis and femur and robotic manipulator. The plaster models were driven by two robotic manipulators to reproduce the hip motion. The accuracy of the robot movement was 0.245mm over the working area according to the validation by an optical tracking system. By combining this system with linear actuators that reproduce the muscle functions, patient-specific muscle function can be simulated, thereby helping clinicians to diagnose and make a treatment plan.