Iatrogenic Sacral Root Entrapment after Iliosacral Screw Fixation in a Patient with Pelvic Ring Fracture: A Case Report

Study Design: Case report. Objectives: Despite precise iliosacral (IS) screw placement, we encountered a case of a neurological deficit due to a bony fragment that remained around the nerve root after reduction of the fracture gap in a patient with a pelvic ring injury. Summary of Literature Review: Percutaneous IS screw fixation is a commonly used procedure because it enables an adequate fixation force to be secured through a minimally invasive method in patients with pelvic ring fractures. Percutaneous IS screw fixation using C-arm fluoroscopy has been well described. In addition, several studies have investigated methods to prevent neurological damage. Materials and Methods: A 48-year-old man was diagnosed with a lateral compression type 1 pelvic ring fracture. Bilateral IS screw fixation was performed in the patient, who had no preoperative neurological abnormalities. He complained of pain around the sacroiliac joint that radiated to the lower leg after percutaneous IS screw fixation, and he was diagnosed with S1 radiculopathy on electromyography. Results: While reviewing the patient’s preoperative computed tomography images, a bony fragment in the fracture gap on the left S1 root was noted. After confirming S1 root entrapment, decompressive laminectomy was performed. Conclusions: Surgeons should be aware that postoperative neurological symptoms may be caused by a bony fragment resulting from the fracture, regardless of screw malposition in percutaneous IS screw fixation. Preoperative planning with meticulous image review and intraoperative neurological monitoring, as well as using full-threaded screws, may help to prevent this problem.