Quantitative Measurements of Knee Alignments in Three-Dimension Bone Models

It is difficult for existing methods to measure the angular, bowing, and rotational knee alignments altogether in 2D radiograph images. We propose an automatic measurement method to quantify these knee alignments in three-dimensional (3D) bone models. Eight important anatomical landmarks of lower limb bones are used to establish lower extremity coordinate systems, in which we introduce seven parameters and discuss their measurements. These seven parameters are used to evaluate these knee alignments. Comparing with 2D radiograph methods, this method can measure both the distances and orientations of the bowing knee alignment, and can clearly visualize the rotational knee alignment.