To analyze the morphologic differences in blowout fracture seen on preoperative CT images compared to intraoperative images.

The present study included 63 patients (63 eyes) with orbital fractures that were repaired by orbital reconstruction between January 2009 and April 2010. We assessed the medial, inferior, and inferomedial orbital fractures and excluded superior and lateral wall fractures. We captured intraoperative blowout fracture images using a camera or endoscope and compared the fracture type (fracture size, fracture surface) seen on intraoperative images with that observed on the preoperative CT images.

The study consisted of patients between 20 and 50 years of age with a mean age of 27.76 years (men: 49 eyes, women: 14 eyes). The proportions of small fractures and medium fractures were similar on the preoperative CT images; however, large fractures were observed more frequently on the intraoperative images. The proportions of mono-fragment fractures and multi-fragment fractures were similar on the preoperative CT images, but multi-fragment fractures, especially inferior orbital fractures, were more frequent on the intraoperative images. Features of the trapdoor fracture differed most between images in terms of fracture size and surface.

The morphology of blowout fractures, especially trapdoor fractures, differed between preoperative CT images and intraoperative images.