A method to estimate in vivo dynamic articular surface interaction.

This paper describes a method to calculate and visualize the proximity of subchondral bone surfaces during dynamic movement. This method combines high-speed biplane radiographic image data and three-dimensional (3D) bone surface information derived from computed tomography to determine subchondral bone motion during dynamic activities. Knowledge of in vivo subchondral bone motion may be useful in the study of osteoarthritis, in biomechanical modeling, and in identifying normal and pathological joint mechanics. This method can be used to identify the regions of close contact during dynamic motion, to calculate the surface area of subchondral bone within close contact, and to determine the changing position of the close contact area during dynamic activities. None of this informations can be obtained using other currently available 3D motion analysis techniques. Example applications showing dynamic in vivo tibio-femoral bone surface motion during canine gait and human one-legged hopping are presented.