Image-Based Matching for Natural Knee Kinematics Measurement Using Single-Plane Fluoroscopy

Abstract

The purpose of the present study is to develop a direct and accurate method for measuring knee kinematics by using single-plane fluoroscopy. The 3-dimensional (3D) position of the bone (in other words, the 6 degree-of-freedom (DOF) parameters) was recovered by matching the digitally reconstructed radiographs (DRRs) generated from the 3D volume model of the bone on the basis of the fluoroscopic image. The root-mean-square error (RMSE) of the overall rotation parameters was within 2.1 degrees. For the translation parameters RMSE took its maximal value of 3.6 mm in the out-of-plane direction. This indicates that the present method has potential for clinical application.