Evaluating the necessity of edema-sensitive imaging in assessing fragility fractures of the pelvis: a retrospective cohort study utilizing the OF Pelvis Classification and Score.

Introduction: The incremental value of edema-sensitive imaging beyond CT in fragility fractures of the pelvis (FFP) remains debated. Research question: Does edema-sensitive MRI provide incremental diagnostic value beyond CT for FFP, and does this influence Osteoporotic Fracture (OF) Pelvis scoring and treatment planning? Materials and methods: In a prospective, single-center diagnostic cohort (April 2021-February 2022), adults with suspected FFP underwent pelvic CT and MRI. OF Pelvis types I-V and the OF Pelvis Score were determined; the score was calculated once with CT information and again with MRI information (retrospective). Primary outcomes were CT sensitivity and specificity for detecting clinically relevant injury (OFP III-V vs. I-II). Secondary outcomes included differences in the OF Pelvis Score and concordance of treatment recommendations. Results: Among 85 screened, 44 were analyzed (31 female, 13 male; mean age 80, range 54-94). CT showed sensitivity 86.9% (95% CI 71.9-95.5); specificity 66.7% (95% CI 29.9-92.5). MRI increased mean OF Pelvis Score (4.25 ± 3.31) versus CT obtained OF Pelvis Score (3.48 ± 3.83; p = 0.029). Despite the score shift, CT- and MRI-based treatment recommendations did not differ significantly (p = 0.317). Nine patients underwent surgery; one CT-missed unilateral sacral fracture required surgery after mobilization failure. Discussion and conclusion: CT showed high sensitivity for clinically relevant OF Pelvis III-V injuries; MRI modestly increased the OF Pelvis Score without materially changing management. A CT-first strategy for routine FFP assessment is supported, with edema-sensitive imaging reserved for diagnostic uncertainty or discordant findings.