Method for calculating the shape of a rod of a pedicle screw system for spinal fusion

A system for calculating a shape of a rod of a pedicle screw system for spinal fusion comprising a workstation having a processing subsystem arranged to:

• a) acquire at least one bidimensional image of a spine of a patient;
• b) acquire a tridimensional image of the spine of the patient;
• c) obtain a tridimensional model of the spine, based on a combination of such tridimensional and bidimensional images;
• d) perform a sagittal balance analysis of the bidimensional image or the tridimensional model to calculate spino pelvic parameters and comparing said spino pelvic parameters with predetermined range values;
• e) apply tridimensional simulated corrections to the tridimensional model of the spine;
• f) calculate corrected spino pelvic parameters on the tridimensional model of the spine corrected with the simulated corrections and checking if the corrected spino pelvic parameters are within the predetermined range values,
• g) in a negative case, repeat steps e)-f);
• i) in a positive case, obtain a tridimensional corrected model of the spine based on such tridimensional simulated corrections, said tridimensional simulated corrections including insertion of a plurality of virtual screws into the tridimensional model of the spine;
• and
• j) calculate the shape of the rod as a mathematical function which best approximates a curve passing through the virtual screw of the tridimensional corrected model of the corrected spine.