Measurement of an intact knee kinematics using gait and fluoroscopic analysis.

A method has been introduced in this paper to measure the kinematics of a knee joint and to use it as a boundary condition to model the knee's mechanical behaviour. A mobile C-Arm fluoroscopy system (Ziehm Vision R) and a CCD camera were used for the measurement of a patient's knee kinematics. The fluoroscopic images were recorded with 12 fps and then sent to Matlab software (Mathworks, Natick, MA, USA) for image processing. In parallel, CT scan images of the knee bones were used to create the 3D anatomical geometry of the knee by aid of Mimics software (Materialise NV). However, the geometrical model of the two medial and lateral menisci was generated from MRI data. The 3D geometrical model of the knee was then sent to Abaqus finite element software (Simulia Dassault Systems) to analyse the knee joint contact loads by introducing the boundary condition which was obtained from fluoroscopic images. The finite element model was used to evaluate the stress distribution on the cartilages during the gait. The result was then compared with the experimental data of gait analysis. The comparison between the results showed a close agreement between the two outcomes.