Estimation of 3D biomechanics parameters of patellar movement using dynamic CT images

Multislice CT scanners have characteristics that offer advantages in clinical applications. The technology is particularly suited for medical applications that require high time performance and high spatial resolution. Patellofemoral tracking is one application that can benefit from multi slice CT characteristics. It is performed to study disturbances in the normal tracking mechanism of the patellar femoral joint. The patellofemoral instability is one condition that generates pain, functional impairment and often requires surgery as part of orthopedic treatment. The analysis of the patellofemoral dynamics has been performed by several medical image modalities. However, most of the methods are based on measurements in 2D images, such as the patellar tilt angle and the lateral shift. Besides, the acquisition protocols are mostly performed at fixed angles. The use of helical multislice CT scanner can allow the capture and display of the joint´s movement performed actively by the patient. In this work we evaluate the use of multi slice high resolution CT technology to evaluate the biomechanics of the patellofemoral joint. The quantitative analysis of the movement is performed by extracting displacement parameters in 3D images between different knee positions. Analyses of these parameters for all frames provided real 3D information about the patellar displacement.