Percutaneous modified iliac screw fixation: technique and clinical experience

Acta Neurochirurgica (2026) 168:20

This study reports clinical experience with a percutaneous modified iliac screw (PMIS) technique for sacropelvic fixation, developed to reduce soft-tissue dissection and avoid limitations of conventional iliac and S2 alar-iliac screws. Ten patients treated between 2014 and 2025 for mainly metastatic spinal disease underwent PMIS under C-arm fluoroscopy with virtual reference lines guiding intra-iliac cancellous screw placement.

Outcomes showed no wound infections, screw prominence complaints, sciatic notch or acetabular violations, or radiographic loosening (except one case requiring removal for progressing infection unrelated to PMIS). Spinopelvic alignment remained stable, and authors conclude PMIS is a safe, minimally invasive alternative warranting larger studies for broader validation.

Percutaneous Modified Iliac Screw (PMIS) Technique: PMIS is a minimally invasive method for sacropelvic fixation that uses fluoroscopic guidance and virtual reference lines to safely insert screws into the intra-iliac cancellous corridor, aiming to overcome drawbacks of conventional iliac screw (CIS) and S2 alar-iliac (S2AI) techniques.

Clinical Outcomes: In a retrospective series of 10 patients, PMIS showed no cases of infection, screw prominence, or screw-related complications, with only one revision required due to unrelated infection progression.

Spinopelvic Stability: Radiographic evaluation demonstrated that spinopelvic parameters (pelvic incidence, pelvic tilt, sacral slope) remained stable from preoperative to final follow-up, indicating maintenance of alignment.

Advantages Over Traditional Methods: PMIS avoids the need for offset connectors, reduces soft tissue dissection, minimizes screw head prominence, and potentially lowers infection and wound complication rates compared to CIS and S2AI methods.