Dynamic MRI Assessment of Normal Knee Kinematics

Abstract

Background: Knee motion is complex and has been studied intensively. The concept of an instant center of rotation postulates that the axis around which the tibia flexes and extends moves with knee flexion and extension. This concept has been contradicted by the concept of fixed axes around which the tibia and patella flex and extend during knee motion. Advanced imaging technologies help to further characterize knee motion and facilitate localization of the axis around which the tibia flexes and extends. Using dynamic magnetic resonance imaging (MRI), the purpose of this study was 1) to establish a setup for dynamic MRI knee measurements, 2) to construct a cadaver knee model and 3) to generate a mathematical algorithm to facilitate a 3-dimensional characterization of knee kinematics and calculate a defined and fixed axis around which the tibia flexes and extends.