Method for determining the screw trajectory of a pedicle bone screw

A method for determining an optimal screw trajectory of a pedicle bone screw comprising the following steps:

• obtaining a computed tomography (CT) image of a target bone area intended to receive the pedicle bone screw;
• establishing an individualized three-dimensional geometric model of the target bone area based on the CT image, the individualized three-dimensional geometric model including bone density information;
• accessing a database comprising a three-dimensional bone area model, wherein the three-dimensional bone area model comprises a bone screw insertion surface and a pedicle traversing surface;
• morphing the three-dimensional bone area model to the individualized three-dimensional geometric model of the target bone area generating a morphed vertebra model comprising the bone screw insertion surface and the pedicle traversing surface of the three-dimensional bone area model as well as the bone density information of the individualized three-dimensional geometric model, wherein the morphing comprises transferring the bone screw insertion surface and the pedicle traversing surface onto the individualized three-dimensional geometric model;
• calculating an optimal screw trajectory of the pedicle bone screw maximizing bone density when bone material is replaced by the pedicle bone screw in the morphed vertebra model of the target bone area;
• and
• outputting the optimal screw trajectory for the pedicle bone screw in the morphed vertebra model of the target bone area.