Percutaneous iliosacral screwing in pelvic ring injury using three-dimensional fluoroscopy

Background: Iliosacral screw fixation is a popular technique for treatment of unstable pelvic injuries involving the posterior ring. However, screw malposition may result in dangerous complications involving injury to adjacent neurovascular structures. This study was conducted in order to evaluate the results and efficacy of using three-dimensional fluoroscopy in the performance of iliosacral screw fixation. Methods: Twenty-nine patients (31 cases, two bilateral) who suffered injury to the pelvic ring requiring surgical treatment were included in this study. According to the Association for Osteosynthesis-Orthopaedic Trauma Association (AO-OTA) classification, there were 14 patients with type B, 13 patients with type C, and 2 patients with a bilateral sacral fracture. The mean age of patients was 39 years. Once the guide pin had been inserted, its safety was confirmed using three-dimensional fluoroscopy; screw fixation was then performed. Eighteen patients underwent percutaneous iliosacral screw fixation and anterior fixation, while 11 patents underwent screw fixation only. Postoperative computed tomography (CT) was performed for evaluation of the screw position, including any invasion into the sacral foramen or canal and neurovascular injury. The perforation of the screw was divided according to the location (sacral zones I, II, and III) and the degree (grade 0, no perforation; grade 1, perforation <2 mm; grade 2, perforation between 2 and 4 mm; grade 3, perforation >4 mm). Results: The mean operation time was 35.6 min, and the mean radiation exposure time was 85.9 s. For accurate location of the guide pin, one patient underwent three-dimensional reconstruction twice. None of the patients required reoperation or suffered any neurovascular injury. Although seven cases involved perforation, all were less than 2 mm (grade 0: 24 cases, grade 1: 7 cases). Conclusions: When performing percutaneous iliosacral screw fixation in a patient with an unstable pelvic ring injury, use of three-dimensional fluoroscopy may allow for accurate location of the screw and result in fewer complications.