Are standard antero-posterior and 20° caudal radiographs a true assessment of mid-shaft clavicular fracture displacement?

AIMS: Decision-making in management of clavicle fractures is often based on the degree of displacement and shortening present on plain radiographs. We aimed to evaluate whether plain radiographs provide an accurate representation of the true displacement present, which can be difficult to image in orthogonal planes.

METHODS: Consecutive high-energy trauma patients with midshaft clavicular fractures requiring further CT imaging of the thorax/abdomen for other associated injuries between 2009 and 2012 were evaluated. The plain radiographs and CT scan were both performed at initial presentation. Displacement and shortening of the clavicle fracture were assessed on the standard clavicle views and then compared with the axial images obtained from CT scans.

RESULTS: 26 patients admitted following a high-energy trauma that necessitated CT scan of chest/abdomen/pelvis were included. All patients also underwent standard clavicle view radiographs at the same initial assessment. Displacement varied from 0 to 233%. Shortening was measured as between 0 and 29 mm. The displacement measured on the CT scan was a mean of 19% greater than the AP view and 11% greater than the 20° caudal. This difference was found to be statistically significant (p = 0.019) between the AP view and the axial view on CT. The difference between 20° caudal views did not extend to statistical significance (p = 0.211). There were no significant differences found between the two modalities on assessment of shortening.

CONCLUSIONS: Plain radiographs give an accurate representation of the shortening present in midshaft clavicle fractures. Displacement may be underestimated if the standard AP and 20° caudal views alone are relied upon.