Safety and efficacy of 2D-fluoroscopy-based iliosacral screw osteosynthesis: results of a retrospective monocentric study

INTRODUCTION: Iliosacral screw osteosynthesis is a well-accepted procedure for stabilization of sacral fractures and iliosacral (fracture) dislocations. MATERIALS AND METHODS: In this monocentric study, safety and efficacy of conventional 2D-fluoroscopic-guided iliosacral screw insertion were evaluated. RESULTS: During a 10-year period (2005–2014), 98 patients between the age of 18 and 65 years received 207 iliosacral screws in 101 procedures. Average patient age was 43.2 years. There were 46 Type B and 40 Type C injuries in the AO/OTA classification, nine patients had a fragility fracture of the pelvis. In three patients, primary radiological data were missing. The indication for surgical treatment was a sacral fracture in 97 patients, a pure iliosacral dislocation in 37 patients and a fracture-dislocation in 31 patients. 70 procedures were performed with the patient in supine position, 31 with the patient in prone position. Surgery was done in a minimal-invasive technique in 76 patients, in 22 patients an open reduction was necessary before screw insertion. 81 patients received a unilateral, 17 patients a bilateral screw osteosynthesis. 199 screws were inserted in S1, only eight screws in S2. 65 patients received two screws unilaterally, ten patients two screws bilaterally. There were no vascular or neurologic complications. During in-hospital stay, there were seven complications, which needed 12 operative revisions: three wound infections, two hematomas, one screw malalignment and one early screw loosening. In 28 patients with 56 iliosacral screws, a pelvic CT-scan was performed during follow-up. A penetration of a cortical layer was diagnosed in 20 of these screws. All penetrations were seen in double screw osteosynthesis of S1. In none of the patients, complaints could be explained by the malalignment of these screws. Five operative revisions were performed during follow-up: two for screw loosening, two for fracture healing problems and one for screw malalignment. Metal removal was performed in 39 patients with 75 screws. 2D-fluoroscopic-guided iliosacral screw osteosynthesis is a safe and efficient procedure in clinical practice. DISCUSSION: A thorough preoperative evaluation of the morphology of the upper sacrum and careful operative procedure are indispensable. Fluoroscopic views in AP, lateral, inlet and outlet must allow recognition of all anatomical landmarks. The indication for double screw osteosynthesis in S1 should be taken with caution. Screw malalignments do not inevitably correlate with complaints.