Doctor's Notes on Shoulder Separation Symptoms, Causes, Treatment, and Recovery Time
A shoulder separation is an injury to the junction between the collar bone (clavicle) and the shoulder (acromion of the scapula); it is also termed an acromioclavicular dislocation or AC; an AC is not a shoulder dislocation. A shoulder separation results in an AC ligament injury; in a severe injury, it may include a bone fracture and injury to the coracoclavicular ligament (CC) and muscles. The type or grade of shoulder separation (AC) is related to the extent of damage to the AC; more serious separations are types III – VI that tear both the AC, CC and muscles in the shoulder and neck. Signs and symptoms are pain at the top of the shoulder (with associated swelling, cuts or bruises) and tenderness or soreness at the AC. Signs and symptoms of more serious injury is an upward pointing lump on top of the shoulder and limited shoulder movement; numbness and/or muscle weakness are signs of possible nerve damage; this is a medical emergency.
The cause of a shoulder separation is when a sharp blow or fall causes the clavicle to be forced away from its connection to the acromion on the scapula. Common causes are contact sports injuries (football, rugby, hockey), falls and car accidents.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.