AC Separation Causes, Symptoms & Treatment Options

The acromioclavicular joint (AC joint) is formed where the clavicle (collarbone) meets the acromion. A capsule and two key ligaments stabilize this joint. An acromioclavicular joint injury typically results from a direct impact to the shoulder. Depending on the ligament damage, the shoulder separation may range from mild to severe, the degree of AC separation.

An AC separation can occur in six different degrees:

• Type I: The AC ligament is sprained or slightly torn but still intact. The joint may be slightly out of place. This is the most common type of shoulder separation.
• Type II: The AC ligament is torn completely through, but the coracoclavicular ligaments are unharmed.
• Type III: The AC joint is completely separated. The AC ligament and the coracoclavicular ligaments are torn. The collarbone injury may cause visible elevation.
• Type IV-VI: These rarer and more serious acromioclavicular joint injuries involve severe displacement or tearing.

AC separations are usually the result of traumatic events, like falling on the shoulder or falling on an outstretched arm.

AC separations and collarbone injuries are common in:

• Cycling
• Football
• Hockey
• Volleyball

Symptoms and the severity of symptoms of shoulder separation will vary depending on the separation grade. If you have an AC separation, you may experience one or more of the following symptoms:

• Tenderness and pain when touching the joint
• A bump on the top of the shoulder where the clavicle ends
• Swelling in the shoulder

If you have experienced a traumatic fall and are experiencing symptoms of acromioclavicular joint injury, make an appointment to see an orthopedic specialist. During your appointment, your doctor will examine the affected shoulder, looking for signs of an AC separation.

In order to make a diagnosis, your doctor may prescribe the following imaging tests:

• X-ray

Lower-grade shoulder separations (type I – III) are almost always treated using non-operative treatments. Non-operative treatments for AC separations include:

• Placing the arm in a sling to limit movement and rest the shoulder
• Icing the area to reduce swelling and therefore pain
• Anti-inflammatory medications to reduce swelling
• Physical therapy to restore range of motion and strength

Once swelling and discomfort improve, a rehabilitation program is recommended to support full recovery from the collarbone injury.

Try these exercises to help address your condition:

Below is a PDF of the Exercise Program

AC Separation

If you experience a higher grade AC separation (Type III-VI), or if your injury is not improving with non-operative treatments, you may require surgery. The goal of surgical treatment for AC separations is to carefully place the joint back into its original position and, if necessary, repair torn ligaments. This surgery is often done through an open incision and often requires a graft to reconstruct the torn ligaments. Occasionally it can be done arthroscopically.

The time it takes you to recover from a shoulder separation will depend on the grade of the separation and the treatment options that are most effective in your recovery. Type I AC separations, treated nonoperatively, can heal in one to two weeks, while type II tears may take two to four weeks.

If you require surgery, immobilization is often needed for the first six weeks after surgery, after which physical therapy is often needed. Recovery and return to sports usually take at least six months following a surgical collarbone injury repair.