Measurement of 3d dynamic joint motion using biplane videoradiography

Abstract

Accurate measurement of in vivo joint kinematics is important for understanding normal and pathological human motion and for evaluating the outcome of surgical procedures. Biplane videoradiography is currently the most accurate method available for measuring in vivo joint kinematics noninvasively. The method uses two X-ray images obtained from different perspectives to deduce precise three-dimensional spatial information of the bones that meet at a joint. The abilities to collect high-quality X-ray images at high frame rates and to process these images in a time efficient manner are key factors determining the feasibility of using modern biplane videoradiography systems to measure human joint motion in vivo. The latest developments in this field include improvements in image quality, software for more efficient and accurate data processing, and the advent of mobile biplane videoradiography systems. Mobile systems enable data capture for a wider range of joints and activities by increasing the effective image capture volume, thereby addressing a major limitation of stationary systems. This chapter summarizes the most recent advances in human motion measurement using biplane videoradiography (also commonly referred to as biplane X-ray fluoroscopy).We begin with some basic considerations related to hardware setup, data capture, and data processing and then describe methods commonly used to evaluate system accuracy. The chapter concludes with a discussion of the relative merits of mobile versus stationary systems as well as some thoughts on potential future applications of biplane videoradiography in human joint motion measurement.