Talar Dome Investigation and Talocrural Joint Axis Analysis Based on Three-Dimensional (3D) Models: Implications for Prosthetic Design

Figure 4

Four parts of circles were defined. (a) A horizontal line which passed through LT was created on the lateral crest plane. Lateral-anterior circle passed through LT and LA and was tangent to the horizontal line. Lateral-posterior circle passed through LT and LP and was tangent to the horizontal line. (b) A horizontal line which passed through MT created the medial crest plane. Medial-anterior circle passed through MT and MA and was tangent to the horizontal line. Medial-posterior circle passed through MT and MP and was tangent to the horizontal line. (c) The inclination angle of the talar dome was the angle between the plane which passed through LT, LA, and LP (lateral crest plane) and the plane which passed through MT, MA, and MP (medial crest plane).