Using 3-Dimensional Fluoroscopy to Assess Acute Clavicle Fracture Displacement: A Radiographic Study
Midshaft clavicle fractures are often treated successfully by nonoperative means. However, recent clinical studies have found benefit from surgical fixation in cases with particular fracture characteristics, such as complete fracture fragment displacement with no cortical contact, and fractures with axial shortening of more than 20 mm. Accurately determining the extent of displacement and shortening can therefore be important in guiding treatment recommendations.
To our knowledge, the literature includes only 2 reports of studies that have compared different radiographic views and their accuracy in measuring fracture shortening, and no study has determined the best radiographic view for evaluating fracture displacement.
We retrospectively studied the cases of 10 patients to determine which radiographic view best captured the most fracture fragment displacement. Acute midshaft clavicle fractures were assessed with simulated angled radiographs created from preoperative upright 3-dimensional fluoroscopy scans.
Results showed that 15° angulated radiographs captured the most fracture fragment displacement. Given this finding, we recommend upright posteroanterior 15° caudal radiographs for midshaft clavicle fractures to best assess the extent of fracture displacement.
This innovative study used 3-D fluoroscopy to capture clavicle fracture images with patients in an upright position. Unlike standard CT, in which patients are supine, this 3-D imaging technology better emulates the patient positioning used for upright radiographs, thereby avoiding potential fracture fragment alignment changes caused by shifts in body position. In addition, 3-D fluoroscopy allows us to create multiple precise simulated radiographic angulations without the magnification error of AP radiographs and, to a lesser extent, PA radiographs. Having a standing PA 15° caudal tilt radiograph obviates the need for CT with 3-D reconstruction. More fine detail may be revealed by CT with 3-D reconstruction than by a standing PA 15° caudal tilt radiograph, but the patient faces less radiation risk and cost with the radiograph.
There is no consensus as to what constitutes the standard radiographic series for clavicle fractures. Radiographic technique can vary with respect to supplemental view angulation, supine or upright patient positioning, and AP or PA radiographic views. Although our study did not address the effect of supine versus upright patient positioning on acute midshaft clavicle fracture displacement, we think that, for all clinical and research purposes, upright 15° caudal PA radiographs should be obtained for patients with acute midshaft clavicle fractures.
Conclusion
Our retrospective study of 10 patients with acute midshaft clavicle fractures and preoperative upright 3-D fluoroscopy scans found that a 15° angulated radiograph most often demonstrated the most fracture fragment displacement. Given these findings, we recommend obtaining an additional PA 15° caudal radiograph in the upright position for patients with midshaft clavicle fractures to best assess the extent of fracture displacement. Accurately identifying the degree of fracture displacement is important, as operative management of completely displaced fractures has been shown to improve clinical outcomes.
