Automatic assessment of the torsional alignment of the knee joint in three-dimension visualization.

Improper radiographic images and manual measurement lead to the incorrect evaluation of the torsional alignment of the knee joint. The paper presents the simple, reliable, and robust methods to assess this alignment in 3D visualization. All methods work on 3D bone models reconstructed from CT scan images and are driven by automatically identified bony landmarks and medial axes of the long bones with virtual reality technology. The measured torsional angles of the femur and tibia have important clinical functions to diagnose the torsional alignment. Experiment results show the proposed approach is efficient, robust and reproducible.