Postoperative Radiographs as Predictors of Clinical Outcome in Unstable Ankle Fractures

This study reviews a group of 80 consecutive displaced ankle fractures treated operatively and followed for an average of 3.2 years. Fractures included bone or combined bone and ligamentous injuries in which the initial talar displacement was greater than or equal to 2 mm. The immediate postoperative roentgenograms were examined for several features, which included widening of the syndesmosis, fibular length, talo-crural angle, talar tilt, presence and size of a posterior malleolar fracture, and an abnormality of the medial clear space. Patients were examined at follow-up per Cedell, and their clinical evaluations were correlated with the analysis of radiographic features and demographic data. Good to excellent results were seen in 80% of the cases. The radiographic factors most predictive of a poor outcome were abnormal medial clear space and the presence of a large (greater than 20%) posterior malleolar fracture (p less than 0.05). Fibular shortening, talar tilt, and syndesmotic widening suggested a poor result, but these findings were not statistically significant. Multiple (two or more) radiographic abnormalities correlated with a poor prognosis. Conversely, a perfect radiographic result did not guarantee an excellent clinical outcome. Older patients and those with a delay between injury and surgery greater than 7 days tended to have a poorer result.