Specifying the Entry Point for a Transiliac-Transsacral Screw in Posterior Pelvic Ring Fixation

Area of Science:

• Orthopedic Surgery
• Radiology
• Biomedical Engineering

Background:

• Posterior pelvic ring injuries require precise stabilization using transiliac-transsacral (TITS) screws.
• Accurate entry point determination is critical for successful percutaneous TITS screw fixation.

Purpose of the Study:

• To propose and validate a universal method for specifying the TITS screw entry point under fluoroscopic guidance.
• To enhance the safety and accuracy of percutaneous posterior pelvic ring stabilization.

Main Methods:

• Retrospective analysis of 239 pelvic CT scans to define the TITS screw entry point.
• Virtual surgical procedures to assess feasibility and accuracy of the proposed entry point.
• Clinical validation of the method in actual surgical procedures, comparing it to previous techniques.

Main Results:

• Virtual procedures confirmed secure placement of 148 S1 and 239 S2 TITS screws.
• Clinical procedures achieved secure placement of 27 S1 and 15 S2 screws with 92.9% grade 1 accuracy.
• The proposed method significantly reduced surgical duration, fluoroscopic shots, and guidewire attempts compared to the previous method.

Conclusions:

• The midpoint between vertebral anterosuperior and posteroinferior corners is a reliable entry point for TITS screws on lateral fluoroscopy.
• This method is applicable for S1 and S2 screws in normal sacra and S2 screws in dysmorphic sacra.
• The universal entry point determination method offers superior efficacy and accuracy for TITS screw placement.