Safe corridors for sacroiliac fixation in pediatric patients

Pelvic ring fractures are rare in the pediatric population and can be treated using sacroiliac screws when needed. The aim of this study was to identify safe anatomical corridors for sacroiliac fixation in different pediatric age groups and also to determine the prevalence of sacral dysmorphism in the study sample.

We measured the dimensions of the horizontal and oblique S1 corridors and the horizontal S2 corridor in pelvic computed tomography scans of 138 children aged 1 to 16 years. The patients were divided into three groups (Group 1, 1-6 years old, Group 2, 6-11 years old; and Group 3, 11-16 years old) to identify safe corridors in each age group. We compared the corridors in terms of cross-sectional areas and estimated the prevalence of dysmorphic sacral bones in the study sample.

Data are presented as medians. For each group, the height, depth, and length were, respectively: Group 1: 9.1 mm, 13.9 mm, and 47 mm; Group 2: 13.5 mm, 15.7 mm, and 55 mm; and Group 3: 15.7 mm, 16.8 mm, and 72 mm. The prevalence of sacral dysmorphism was high (44.2%).

In Group 3, 7.0 mm screws were safe in all three corridors. For Group 2, the oblique S1 corridor could accommodate 7.0 mm screws, whereas in the other studied corridors, the 3.5 mm screw would be better indicated. For Group 1, the oblique S1 corridor was best suited, and only for the 3.5 mm screw.