In-screw cement augmentation for iliosacral screw fixation in posterior ring pathologies with insufficient bone stock

Minimal invasive screw fixation is common for treating posterior pelvic ring pathologies, but lack of bone quality may cause anchorage problems. The aim of this study was to report in detail a new technique combining iliosacral screw fixation with in-screw cement augmentation (ISFICA).

The patient was put under general anesthesia and placed in the supine position. A K-wire was inserted under inlet-outlet view to guide the fully threaded screw. The screw placement followed in adequate position. Cement was applied through a bone filler device, inserted at the screwdriver. The immediate control of cement distribution, accurate screw placement and potential leakage were obtained via intraoperative CT scan.

Twenty consecutive patients treated with ISFICA were included in this study. The mean age was 74.4 years (range 48-98). Screw placement, possible cement leakage and screw positioning were evaluated via intraoperative CT scan. Postoperative neurologic deficits, pain reduction and immediate postoperative mobilization were clinically evaluated.

Twenty-six screws were implanted. All patients were postoperatively, instantly mobilized with reduced pain. No neurologic deficits were apparent postoperatively. No cement leakage occurred. One breach of the iliac cortical bone was noted due to severe osteoporosis. One screw migration was seen after 1 year and two patients showed iliosacral joint arthropathy, which led to screw removal.

ISFICA is a very promising technique in terms of safety, precision and initial postoperative outcome. Long-term outcomes such as lasting mechanical stability or pain reduction and screw loosening despite cement augmentation should be investigated in further studies with larger patient numbers.