Preoperative Planning and Simulation for Pedicle Screw Insertion Using Computed Tomography-Based Patient Specific Volume Rendering Combined with Projection Fluoroscopy

Pedicle screw insertion has been a standard processes for stabilizing the spine [1]. Spinal surgery can be classified as either minimally invasive or open, based on differences in the size of incisions: minimally invasive surgery implants the pedicle screw based on intraoperative fluoroscopic images to ensure the entry point and trajectory, and open surgery implants the pedicle screw based on identification of anatomic landmarks; open surgery needs experienced surgeons. In both minimally invasive and open surgery, the location of the screw can be observed using a postoperative computed tomography (CT) image to evaluate the accuracy of the screw placement to improve the implant method [2-4]. The procedure of pedicle screw insertion is complicated and has a steep learning curve. Several institutions have reported the complication rates for pedicle screw surgery from 3% to 55%, with a rate of malpositioning from 1.5% to 6.7% [5-13] and breach rates from 1.5% to 58% [12,14,15,16]. However, these results were not comprehensive due to a lack of reports from small medical centers and newer surgeons. The breach rates are related with the years of experience of the surgeon; overall breaches and medial breaches are 12.9% and 8.0%, respectively, for surgeons with less than five years of experience, and they are 10.8% and 3.5% [17], respectively, for surgeons with more than five years of experience [17]. These results illustrate that the medial breach rate was significantly lower for the experienced surgeons.