[Isolated fractures of the orbital floor].

BACKGROUND: The goal of this retrospective study was quantitative calculation of area and volume of isolated orbital floor fractures from computed tomography (CT) and correlation of these data with post-traumatic ophthalmologic findings.

PATIENTS AND METHODS: A total of 76 patients with isolated orbital floor fractures were evaluated radiologically and clinically. CT scanning was performed in coronal sections (1.5-mm to 3.0-mm slice thickness) with contiguous table feed. Orbital floor and fracture area as well as volume of displaced tissue were measured and calculated from the CT dataset. The relation of quantitative CT data to ophthalmologic findings (motility, diplopia, and globe position) was assessed statistically.

RESULTS: Calculation of the CT dataset revealed a mean orbital floor area of 6.33+/-1.05 cm(2), a mean fracture area of 2.60+/-1.14 cm(2), and a mean volume of displaced tissue of 1.16+/-0.80 cm(3). Volume of displaced tissue correlated significantly with ophthalmologic findings (p< or =0.01). Fracture area correlated significantly with globe position (p< or =0.01) and was less associated with diplopia and motility disturbances (p<0.10).

CONCLUSION: Efficient evaluation of two-dimensional CT data enables quantitative assessment of orbital floor fractures. Position and function of the globe are mainly affected by the volume of displaced periorbital tissue.