Acromioclavicular (AC) joint injury

Injury to the joint on top of the shoulder, usually from a fall onto the shoulder.

Overview

An acromioclavicular joint injury involves the ligaments at the top of the shoulder where the collarbone meets the shoulder blade. It commonly results from a direct fall and ranges from mild sprains to complete separations.

Symptoms

Pain and tenderness over the top of the shoulder
A visible bump in higher-grade injuries
Pain with reaching across the body
Pain lying on the affected side

Causes

Fall directly onto the shoulder
Contact sport collisions
Direct blow to the joint

Treatment

Relative rest and pain management early on
Progressive strengthening of the shoulder
Gradual return to sport
Surgical opinion for high-grade separations