Figure 2

Accurate measurement of three-dimensional TKR kinematics using fluoroscopy. Model-based shape matching techniques were applied to (A) the acquired two-dimensional fluoroscopy images by (B) superimposing surface models of the components and embedded radiopaque markers and iteratively adjusting their three-dimensional pose to match the TKR silhouette. (C) Joint angles, including flexion, valgus, and axial rotation, were determined from the relative orientation between the femoral component and metal tibial baseplate and between the femoral component and polyethylene tibial bearing in each image.