Background and importance: This article reports an unexpected complication of percutaneous pedicle screw fixation at the L5-S1 level.
Clinical presentation: We describe a 66-year-old man who underwent anterior lumbar interbody fusion followed by percutaneous pedicle screw fixation at the L5-S1 level. The Sextant pedicle screw system was used. The patient experienced postoperative sacroiliac joint syndrome caused by the screw head and rod tip. In the immediate postoperative period, the preoperative right-side leg pain improved, but the patient complained of left-side buttock and leg pain. The left-side screws were removed, and after revision surgery, the left-side pain disappeared. However, at that time, right-side pain recurred. We found that the screw head and rod had violated the iliac crest and the sacroiliac joint, causing referred pain rather than radicular pain. After the screw head was repositioned and the rod was replaced with a new shorter rod with a blunt end, the patient's symptom was relieved.
Conclusion: Surgeons should be aware of this unprecedented adverse effect when planning percutaneous pedicle screw fixation at the L5-S1 level. An android pelvis with a narrow and high iliac crest can be a risk factor. Careful preoperative evaluation and more accurate surgical technique are needed to prevent this type of complication.