Objective: In trauma patients, gas (vacuum phenomenon) in the sternoclavicular joints could represent sequelae of significant distraction forces and thus serve as a potential marker for sever intrathoracic injury. We envaluated the significance and frequen y of the finding of gas in the sternoclavicular joints on chest CT of patients with blunt trauma.
Subjects and Methods: We prospectively studied all chest CT examinations performed at our institution over a 14-week period for the finding of gas in the sternoclsavicular joints. Chest CT examinimation (n = 267) were performed in 234 patients. We excluded data fr4om foolow-uip CT exaqminations (n = 33), limiting our evaluation to the initial CT examination for each patient. Of the study population, 103 patients (83 men and 20 women) who ranged in age from 14 to 79 years (man, 40 years) had sustained blunt chest trauma. For all trauma patients, we recored the mechanism of injury and the associated throacic injuries.
Results: CT revealed has in the sternoclavicular hjoints in 47 patients (21%). Gas was unilateral in 27 patients and bilateral in 20 patients. Sternoclavicular joint gas was seen in 39 (38%) of the 103 trauma patients but as found in only eight (6%) of the 131 nontrauma patients (p < .0001). In the 39 trauma patients with sternoclavicluar joint gas, associated thoracic injuries were seen in 17 patients (44%); either a sterval fracture or a retrosternal hematoma was seen in three patients. Radiographically evident thoracic injury was revealed in 20 (31%) of the 64 trauma patients who had no gas in the sternoclavicular joint; however, 10 of these 20 patients had either a sternal fracture or a mediastinal hematoma.
Conclusion: Although gas in the sternoclavicluar joints is more frequantly seen in apatenty with blunt chest trauma than in patients undergoing chest CT for other indications, this finding does not indicate a greater risk of significant mediastinal or thoracic injury.