Radiologic evaluation of dens fracture. Role of plain radiography and tomography.

A retrospective study of 50 dens fractures was performed. In 47 of 50 cases (94%), plain radiographs disclosed the fracture. Initial cross-table lateral view alone showed the fracture in 43 cases. In the remaining four cases, routine plain films revealed the fracture: open-mouth view in three cases and lateral skull view in one case. In 3 of 50 cases (6%), plain films were negative, and fractures were seen only on tomography. Conventional circular tomography was performed in 26 cases; results were divided into 3 categories according to the significance of the findings: Category I, tomography confirmed plain radiographic findings, but added no further information; Category II, tomography detected additional findings or showed the extent of injury better than plain radiography; Category III, fracture was only seen by tomography. There were 19 cases in Category I, 4 in Category II, and 3 in Category III. Careful evaluation of plain radiographs remains the primary method for diagnosis of dens fractures. Tomography should be performed whenever plain radiographs or clinical symptoms are suspicious for dens fracture. In addition, tomography is useful to define the fracture level and pattern, which are important factors in the management of these injuries.