A cadaveric study of induced isolated orbital floor fractures and implications for surgical decision-making: comparison of two preoperative imaging modalities.

Computed tomography (CT) is the gold standard for the diagnosis of isolated orbital floor fractures, while cone beam computed tomography (CBCT) is an alternative. The aim of this study was to compare the diagnostic accuracy of CT and CBCT for isolated orbital floor fractures. Forty-eight isolated orbital floor fractures were systematically induced in cadaver orbits. CBCT and CT scans of each cadaver head were performed and the image data imported into ProPlan CMF for analysis. The orbital floor area (OFA), orbital defect area (ODA), and peri-orbital tissue herniation were evaluated. Surgical decision-making differed significantly according to the imaging modality (P = 0.031). The odds of decision discrepancy between CBCT and CT were higher with increasing ODA/OFA ratios, when adjusted for peri-orbital tissue herniation and fracture localization (P = 0.026). An ODA/OFA ratio cut-off value of >36.25% had a sensitivity of 100% and specificity of 71% (area under the curve 0.83, P = 0.011) for predicting discrepancies between CBCT and CT in surgical decision-making. In this cadaveric study, CT and CBCT were diagnostically equivalent for isolated orbital floor fractures with an ODA/OFA ratio ≤36.25%. However, fractures exceeding this threshold may be better evaluated by CT to avoid discrepancies in surgical decision-making.