A shoulder separation injury occurs when trauma damages the ligaments around the acromioclavicular (AC) joint. It's where the collarbone (clavicle) meets the shoulder blade (scapula). If the injury is severe, part of the shoulder blade may separate from the collarbone.

How is acromioclavicular separation treated?

Treatment is typically an arm sling, bed rest, ice and heat therapy, and anti-inflammatory drugs. Most people recover full motion of the shoulder and arm within 6 to 8 weeks, often with the assistance of physiotherapy.

What is the most common cause of an acromioclavicular joint separation?

The most common cause of an AC joint separation is falling on the shoulder (Fig. 3). As the shoulder strikes the ground, the force from the fall pushes the scapula down. The collarbone cannot move enough to follow the motion of the scapula.