CT-based three-dimensional fracture mapping reveals characteristic patterns in pelvic insufficiency fractures

Pelvic insufficiency fractures are increasingly common in older adults and frequently involve the posterior pelvic ring. However, their population-based three-dimensional distribution has not yet been systematically characterized across the complete Fragility Fractures of the Pelvis (FFP) classification. This study aimed to generate a standardized CT-based three-dimensional fracture map, identify reproducible anatomical hotspots, and visualize fracture distribution across FFP types I-IV.

CT datasets from 67 geriatric patients with pelvic insufficiency fractures (mean age 82.78 ± 6.84 years; 77.6% women) were retrospectively analyzed. Fractures were classified according to the FFP classification of Rommens and Hofmann, segmented in 3D Slicer, registered to a standardized pelvic template, and visualized as frequency-based three-dimensional heatmaps in Blender.

A total of 184 fracture lines were mapped. Fracture clustering was most pronounced in the sacral alae, accounting for 54% of all mapped fracture locations, followed by the parasymphyseal region (22%) and the remaining anterior pelvic ring (15%). Iliac wing and acetabular involvement was less frequent, accounting for 6% and 3%, respectively. FFP-specific heatmaps demonstrated a transition from isolated anterior fractures in FFP type I to progressively broader posterior and bilateral involvement in FFP types II-IV.

Standardized CT-based three-dimensional fracture mapping identified the sacral alae as the principal hotspot of pelvic insufficiency fractures and visualized characteristic spatial patterns across the FFP classification. This approach provides an anatomical framework for improved CT interpretation and future biomechanical, diagnostic, and surgical-planning studies.

Pelvic insufficiency fractures are an increasing consequence of osteoporosis, but their three-dimensional distribution remains poorly understood. CT-based heatmapping identified the sacral alae as the principal fracture hotspot and visualized progressive posterior extension across the FFP classification. These findings improve the anatomical understanding of osteoporotic pelvic fragility fractures.