Using Three-Dimensional Quantitative CT Models to Compare Density Patterns Across Pelvic Fractures

Between 1990 and 2007, the population-adjusted incidence of pelvic ring fractures increased from 27.24 to 34.30 per 100 000 capita. Measuring bone density would aid in surgical planning for patient-specific treatment after traumatic pelvic injuries to decrease the need for repeat surgery. Opportunistic quantitative CT has recently been used to provide bone density data without the need for an additional measurement through dual-energy radiograph absorptiometry, in addition to providing more detailed information about the density distribution. The purpose of this study was to determine whether locations of pelvic fractures correlated with differences in bone density across the fracture and low-density regions.

After retrospective study of clinical CT scans for trauma patients taken on a calibrated CT scanner, 24 scans were included. Medical image processing software, three-dimensional Slicer, was used to segment the innominate bone while accounting for displacement. Density data analysis done through Python 3.10 compared proximal and distal segments and density by region of the innominate bone.

Of these 47 fractures, 43 (91.5%) occurred in low-density regions. Along with this, we found an absolute mean difference of 16.29 mg/mL (P < 0.005) between proximal and distal segments of the fracture.

With this being one of the first studies using quantitative CT to measure bone density across fractures, these data indicate that studying fractures using three-dimensional quantitative models is a useful method to analyze risk factors for pelvic fractures, both in trauma and osteoporotic fragility fractures.

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