Relation between preoperative computed tomographic criteria of injury to the nasofrontal outflow tract and operative findings in fractures of the frontal sinus

Injury to the nasofrontal outflow tract is important in the treatment of fractures of the frontal sinus. In 2008 preoperative computed tomographic (CT) criteria or signs of such injuries were proposed and stated to be reliable. The aim of this study was to evaluate the validity of these criteria by comparing the radiological evidence with the operative findings. Thirty-nine patients for whom the data from preoperative CT could be compared with operative findings were eligible for the study, all but 4 of whom had at least one indicator of injury to the outflow tract. Patients whose tracts were found to be obstructed at operation had at least 2 preoperative CT signs of obstruction of the tract. If the outflow tract was obstructed all 3 criteria were significantly more likely to be present than if it was intact (p = 0.02). Two criteria or fewer did not correlate significantly with obstruction. Fractures were managed by reconstruction (n = 18), obliteration (n = 11), or cranialisation (n = 10). This study is the first to our knowledge to examine the correlation between preoperative CT criteria and operative findings, and there was a significant difference in the number of criteria present depending on whether the outflow tract was intact or injured. Our findings allow for more accurate planning of management of fractures of the frontal sinus.