gms | German Medical Science

Objectives: Percutaneous iliosacral screw fixation provides a minimal invasive technique for osteosynthesis of the majority of posterior pelvic ring fractures or dislocations. Still, it remains a technically demanding procedure that carries significant risks for the patient. Anatomic variability or dysplasia, obesity, or bowel gas may limit the feasibility and safety of the technique.

The aim of this study was to evaluate the safety and reproducibility of a new standardised planning methodology that uses only a customary picture archiving and communication system (PACS) with the pre-operative computer tomography (CT) scan data.

Methods: Using a standard PACS (Merlin Diagnostic Workcenter; Phoenix PACS GmbH; Freiburg (D)) iliosacral screws into the S1 body were prearranged adhering to a framed planning methodology. Screw trajectories were determined only using custom multiplanar reconstruction of CT data and the integrated meas-uring tools. Intraoperatively, the planned entrypoint of the screw was reproduced in a strict lateral view and a guide-wire was introduced accordingly aiming towards the promontory. After inserting the wire 4 cm, before passing the neuroforamen, the intended tract was verified by inlet and outlet views.

After the methodology became established and standardised in April 2017, all consecutive patients treated with at least one S1 iliosacral screw following the described planning procedure were analysed regarding screw position and postoperative neurological symptoms. In all patients, a postoperative CT scan of the pelvis was performed.

Results and conclusion: After modelling the planning procedure in April 2017 till December 2017, a total of 49 S1 iliosacral screws (34 patients) were placed by one surgeon following the elaborated methodology. A second surgeon was introduced to the methodology and subsequently performed a total of 7 screw placements (4 patients) adhering to the planning procedure. None of the patients suffered from mal-positioning of the screws or from iatrogenic neurological symptoms.

The novel standardised planning methodology offers reproducible and safe placement of iliosacral screws on the S1 level with resources that are commonly available in hospitals owning a CT. The described planning procedure could help to reduce potential complications.