Surgical technique of iliosacral screws placement guided by 3D printing template in sacral fractures

Abstract

Objective To investigate the feasibility and accuracy of a drill template for the placement of iliosacral screws based on digital design and 3D printing technology. Methods The preoperative CT images of a 35-year-old male patient with pelvic fracture were collected. According to the Dennis classification, the type of pelvic posterior ring fracture was sacral region II. The pelvic front ring fracture involved the contralateral superior ramus and inferior ramus of the pubis. The data was reconstructed by 3D imaging reconstruction workstation. The operation was simulated and the individual drill template was designed on the virtual 3D model according to the surgical procedure. With the 3D printing technology, the individual drill template and the solid pelvic model were produced. Results Preoperative simulation with the 3D printed solid model confirmed the effectiveness of the template. During the surgery, the drill template was used to guide the placement of iliosacral screws. The implantation of iliosacral screw cost 30 min, with intraoperative blood loss of 50 ml and no blood transfusion. The wound healed primarily. Intraoperative CT was used only once after the entire pedicle screw had been inserted. The method significantly reduced operation time and radiation exposure for the members of the surgical team. Drill template was used in case of iliosacral screws implantation. The entry point and orientation of the screws were all consistent with virtual schemes. The position of pedicle screw was good and no screw worn out of the pedicle cortex. 3D printed pelvic model and individual designed drill template were technically feasible and result in accurate and precise screw placement. Overall, iliosacral screw was placed and the accuracy of screw placement was confirmed with postoperative X-ray and CT scanning. Template and the corresponding anatomical landmark fitted well. A 3-month followup demonstrated properly functional recovery was reached. No biological complications were encountered and no implant failures occurred during the entire followup period. Conclusion By means of digital design and 3D printing technology, accurate placement of individualized iliosacral screws can be realized. This technology improves the safety profile of this fixation technique and should be further studied in clinical applications. Key words: Pelvis; Fractures, bone; Computer-aided design; Imaging, three-dimensional