Morphologic Alterations of the Sternoclavicular Joint following Ipsilateral Clavicle Fractures

Rationale: To our knowledge, no study has investigated concomitant injuries of the sternoclavicular joint (SCJ) in acute clavicle fractures. The purpose of this study was to determine the effect of an ipsilateral clavicle fracture on the SCJ in a systematic computer tomography (CT) morphologic evaluation. Methods: CT scans in the axial and coronal plane of 45 consecutive patients with clavicle fractures were retrospectively analyzed. The scans were assessed regarding anatomic congruence of bilateral SCJs-joint space width (JSW); the position of bilateral medial clavicles (PC); and the non-fusion of epiphyses, arthritis, calcifications, and intra-articular gas. Results: The mean SCJ JSW was significantly different in the coronal (cJSW; 8.70 mm +/- 2.61 mm in affected vs. 7.63 mm +/- 2.58 mm in non-affected side; p = 0.001) and axial plane (aJSW; 9.40 mm +/- 2.76 mm in affected vs. 9.02 +/- 2.99 in non-affected SCJs; p = 0.044). The position of the medial clavicle showed a significant difference in the coronal plane (cPC; 14.31 mm +/- 3.66 mm in the affected vs. 13.49 +/- 3.34 in the non-affected side; p = 0.011), indicating a superior shift. Conclusion: Acute clavicle fractures may be associated with an enlargement of the ipsilateral SCJ space width and a superior shift of the proximal clavicle. Both morphologic alterations could indicate concomitant injuries of the SCJ as well as a potential increase in the risk of SCJ instability.