Measurement of fracture size using the picture archiving communication system in an outpatient clinic for factors that influence postoperative enophthalmos in adult inferior orbital wall fractures

PURPOSE: This study aims to determine the relationships between postoperative enophthalmos, preoperative enophthalmos, and fracture sizes in adults with inferior orbital wall fractures. METHODS: The records of 31 patients who had operations for pure orbital floor blowout fractures from March 2003 to February 2004 were retrospectively reviewed. Using the Picture Archiving Communication System, we measured fracture sizes according to the orbital computed tomography results. We calculated fracture sizes according to the supposition that the fracture was a 2-dimensional figure. Hertel exophthalmometry was performed on preoperative day 1 and 3 months postoperatively. RESULTS: Mean changes of enophthalmos were 2.80 mm (P < 0.05, paired t test). The mean fracture size was 6.11 cm (range, 3.56-11.73 cm). Fracture size was a more accurate predictor of postoperative enophthalmos than the degree of preoperative enophthalmos (Pearson correlation; with preoperative enophthalmos = 0.513, with fracture size = 0.743, P < 0.05). In linear regression analysis, preoperative exophthalmometry measurements contributed approximately 27.1% to postoperative enophthalmos, whereas fracture size contributed approximately 54.3% (P < 0.05). In multiple regression analysis, the equation was Y = 0.313X + 0.464X′ - 0.684 (X is the size of fracture; X′, preoperative exophthalmometry measurement). The above 2 factors explained 82.3% of the total postoperative enophthalmos variance. Other factors, which contribute approximately 18%, might include time between insult and corrective surgery. CONCLUSIONS: In our study, fracture size was a better predictive factor for postoperative enophthalmos than preoperative exophthalmometric measurement. With our method, postoperative enophthalmos can be predicted more conveniently in a clinical setting, and decisions regarding the timing of early surgical reduction were made easier.