What is it: Sprains and dislocations can occur at the sternoclavicular joint from direct trauma or indirectly from a compression force applied to the shoulder.
How does it present: Sprain injuries to the sternoclavicular joint may present only with pain and localized swelling after an appropriate injury. Dislocations are more commonly anterior if they occur and may also present with a prominence of the medial clavicle at the sternoclavicular joint. Posterior dislocations are less common but may become a medical emergency due to compression of the airway of subclavian vessels by the posteriorly displaced clavicle.
Common exam findings: With sprains of the sternoclavicular joint, you may note swelling over the area and tenderness. With anterior dislocations, a prominence of the medial clavicle is best seen looking at the patient from the superior position while they are supine. Posterior dislocations may rapidly progress to additional symptoms including airway difficulty, hoarseness, and evidence of poor upper extremity vascularity on the affected side (e.g., arm discoloration, swelling and decreased strength of pulse). This is a medical emergency.
Tests and treatment: Treatment of sprains is usually conservative with protected range of motion and avoidance of further trauma until healed. Anterior dislocations may be difficult to diagnose on x-ray alone, requiring CT scan to further evaluate. Such dislocations are often treated conservatively, but may consider referral to orthopedics for a true dislocation. Posterior dislocations can become medical emergencies and may need to be reduced at the scene of injury by: (1) placing a rolled up towel between the patient's shoulder blades while lying supine; and (2) placing posterior pressure on the shoulders. If necessary, more aggressive maneuvers may be considered by appropriately trained physicians.