An analytical method to create patient-specific deformed bone models using X-ray images and a healthy bone model

Area of Science:

• Medical imaging
• Biomechanical engineering
• Orthopedic surgery

Background:

• Patient-specific bone models are crucial for surgical planning and implant design.
• Existing methods may require complex imaging or lack accuracy for deformed bones.

Purpose of the Study:

• To develop an algorithm for generating patient-specific 3D femur and tibia models with deformities using only X-ray images.
• To enable accurate visualization for surgical procedures like external fixation.

Main Methods:

• A generic healthy bone model is deformed using free-form deformation guided by interpolation functions (polynomial or cubic spline).
• Interpolation functions are derived from simple measurements on X-ray images of the diseased bone.
• An error measure is defined to quantify the accuracy of the generated models.

Main Results:

• The algorithm successfully generates 3D bone models that reflect the actual bone geometry, including deformities.
• Deformed tibia models were validated by orthopedic surgeons, showing satisfactory accuracy.
• The generated models are suitable for visualizing external fixation procedures.

Conclusions:

• The proposed algorithm offers a reliable and efficient method for creating patient-specific 3D bone models from X-rays.
• This technique can enhance the planning and execution of orthopedic surgeries involving bone deformities.
• The generated models aid in the visualization of fixation procedures, improving surgical outcomes.