Optimal ilio-sacral screw trajectory in paediatric patients : a computed tomography study

Area of Science:

• Orthopedic Surgery
• Pediatric Spine Surgery
• Radiology

Background:

• Pelvic fixation is challenging in pediatric spinal deformity correction.
• Optimal ilio-sacral screw trajectory for pediatric patients is not well-defined by computed tomography (CT) studies.
• Preventing screw malposition is critical for surgical success and patient safety.

Purpose of the Study:

• To identify the optimal trajectory for ilio-sacral screw placement in pediatric patients using pelvic CT.
• To analyze the influence of age and sex on screw trajectory and anatomical parameters.
• To establish guidelines for safe and effective ilio-sacral screw insertion.

Main Methods:

• Pelvic CT scans from 80 children (categorized by age and sex) were analyzed.
• A secure triangular corridor parallel to the S1 endplate was delineated using fixed landmarks.
• The optimal screw insertion angle and anatomical parameters were measured and statistically analyzed (Student's t test).

Main Results:

• The mean optimal screw insertion angle varied significantly with age (p=0.004) but not sex (p=0.55).
• Mean optimal screw length was 73.4±9.9 mm.
• Anatomical spinal canal parameters differed based on age and sex, particularly in older children.

Conclusions:

• Age is a significant factor influencing optimal ilio-sacral screw positioning in pediatric patients.
• Sex does not significantly affect screw trajectory, but anatomical parameters vary.
• These findings provide crucial data for enhancing the safety and ease of ilio-sacral screw placement in pediatric spinal surgery.