William Ledoux, Ph.D.
VA Center of Excellence for Limb Loss Prevention and Prosthetic Engineering
E-mail: wrledoux@u.wa...


TITLE:

"Using Biplane Fluoroscopy to Quantify Foot Bone Motion"

ABSTRACT:

Tracking the motion of the bones of the foot is technically challenging. Computerized infrared
camera systems with surface markers can be used, but skin motion artifact is a problem and
small foot bones necessitate grouping. X-ray stereophotogrammetry has also been used in
controlled static positions, but these methods are invasive and dynamic foot motions were not
reported. Others have also evaluated the orientations of the bones of the foot using
time-sequence MRI; this requires positioning the feet in static locations which does not
necessarily represent bone motion during gait. More recently, retro-reflective markers with
bone pins have been used to quantify foot bone motion. These studies represent the gold
standard for in vivo foot bone motion, but the invasiveness limits its utility. Single plane
fluoroscopy has been used to study hindfoot kinematics; while the flexibility and utility is
obvious and attractive, the complex anatomy of the foot with many small, occluding bones limits
this system. Others have used dual C-arms to study ankle motion; however, this setup required
quasi-dynamic data collection as subjects were not able to walk unfettered through the field of
view. Despite this progress, the ability to use a biplane fluoroscopy system to study foot bone
motion remains incompletely explored to date. In this talk we will review the exist
methodologies for quantifying foot bone motion and describe the biplane fluoroscope that is
under development at the VA Puget Sound.