Differential Diagnosis for Separated Shoulder

• Single most likely diagnosis
  • Acromioclavicular (AC) joint separation: This is the most common diagnosis for a separated shoulder, occurring when the ligaments that hold the AC joint together are torn, causing the clavicle to separate from the acromion.
• Other Likely diagnoses
  • Clavicle fracture: A fracture of the clavicle can cause similar symptoms to a separated shoulder, including pain, swelling, and limited mobility.
  • Shoulder dislocation (glenohumeral joint): Although less common than AC joint separation, a dislocation of the shoulder joint can also present with similar symptoms.
  • Rotator cuff injury: Injuries to the rotator cuff muscles or tendons can cause shoulder pain and limited mobility, potentially mimicking a separated shoulder.
• Do Not Miss diagnoses
  • Brachial plexus injury: A severe injury to the brachial plexus can occur with a separated shoulder, particularly if there is a significant displacement of the clavicle or humerus, and can lead to permanent nerve damage if not promptly diagnosed and treated.
  • Vascular injury: Rarely, a separated shoulder can be associated with injury to the subclavian artery or vein, which can lead to severe bleeding or other complications if not recognized and treated promptly.
• Rare diagnoses
  • Sternoclavicular joint dislocation: Although rare, a dislocation of the sternoclavicular joint can occur and may present with similar symptoms to a separated shoulder.
  • Scapular fracture: A fracture of the scapula can cause shoulder pain and limited mobility, but is less common than other diagnoses on this list.