MR imaging of the sternoclavicular joint following trauma.

The purpose of this study is to describe the magnetic resonance imaging (MRI) findings of the sternoclavicular (SC) joint seen in patients who presented to our department with joint pain related to trauma. Clinical history and MRI findings on 41 patients were reviewed retrospectively to establish types and frequencies of soft tissue injuries and subluxations. Because both SC joints were imaged, the asymptomatic joints were used as a control group. Articular disk injuries were seen in 80% of patients. Injuries of the anterior, posterior, interclavicular and costoclavicular ligaments were seen in 73%, 39%, 29% and 14% of patients, respectively. Most clavicular subluxations were in the superior and posterior directions. Posterior impingement of mediastinal structures was seen in cases of posterior clavicular subluxation as well as in cases of retrosternal inflammatory or fibrotic tissue without clavicular subluxation. Biomechanical models of the SC joint are discussed to explain how different ligamentous injuries typically result in different types of subluxations.