Determining an optimal placement of a pedicle screw

A device for planning a placement of pedicle screws, comprising:

• a processing unit,
• wherein the processing unit is configured to receive a global model data set representing:
• a first model surface of a first human vertebra and a first pedicle screw model positioned in a pedicle section of the first model surface,
• a second model surface of a second human vertebra and a second pedicle screw model positioned in a pedicle section of the second model surface, and
• a model arrangement of the first human vertebra relative to the second human vertebra,
• wherein the processing unit is configured to receive image data representing at least a first image of a first human vertebra, a second image of a second human vertebra and an arrangement of the first image relative to the second image,
• wherein the processing unit is configured to adapt the global model data set to the image data, the adapted model data set representing:
• a first adapted model surface adapted to the first image of the first human vertebra,
• a second adapted model surface adapted to the second image of the second human vertebra, and
• a correspondingly adapted model arrangement of the first adapted model surface relative to the second adapted model surface,
• wherein the adapted model data set further represents correspondingly adapted first and second pedicle screw models.