Preoperative Pedicle Screw Placement Planning using Particle Swarm Optimization

Abstract Correct pedicle screw placement is essential in scoliosis surgery to ensure patient safety and surgical success. We propose a method to compute screw placements from vertebrae CT scans by mapping the entry point from a dictionary and then optimize the placement with particle swarm optimization. Our approach was tested on T6, T12, and L4 vertebrae and evaluated using the Gertzbein-Robbins classification (GR), the Zdichavsky grading system (ZG). Furthermore, a specialized surgeon assessed the placements. The results indicate that 89.58% of the total placements were valid. Among these valid placements, 46.51% were rated an A according to the GR and the other 53.49% were rated as B. All valid placements were Ia according to ZG. The medical assessment showed that 41.86% and 20.93% were optimal placements and good placements respectively.