Scapulothoracic dissociation: are there reliable chest radiographic findings?

Abstract

Purpose: To delineate chest radiographic (CXR) findings in scapulothoracic dissociation (SD), defined as a closed, blunt-force partial amputation of the forequarter dominated by brachial plexus and appendicular vascular injuries. Methods: Radiographs were available in 8 of 11 cases of SD identified by retrospective search of patient databases. Recumbent, nonrotated portable CXR views from 58 male individuals without SD seen in the emergency department for reasons other than trauma served as controls. Measurements on CXRs from controls were used as the basis on which to define normal ranges for scapulothoracic ratios. The CXRs from the eight study patients were evaluated by two emergency radiologists for the presence of a fracture diastasis greater than 1 cm, dislocation, soft tissue hematoma of the axilla, extrapleural apex, or superior mediastinum, and the scapulothoracic ratio was measured. Results: On the basis of the control patients' CXRs, the medial margin of the glenoid was determined to represent the best landmark for quantifying lateral scapular displacement. However, only one case of SD met the radiographic criteria. Conclusion: SD is a functionally devastating and life-threatening consequence of severe blunt polytrauma. Commonly overlooked initially, in most cases SD shows suggestive findings. While the scapulothoracic ratio appears to be insensitive as a measure, the combination of apicolateral pleural cap and axilla or mediastinal hematoma is suggestive of great vessel injury and should raise suspicion for SD.