Understanding shoulder separation and how it’s treated

What Is an AC Joint Dislocation?

The acromioclavicular (AC) joint is where the collarbone (clavicle) meets the shoulder blade (scapula) at the top of your shoulder. A dislocation of this joint, also called a shoulder separation, happens when the ligaments that hold the bones together are stretched or torn.

What Causes AC Joint Dislocation?

AC joint dislocation is usually caused by a direct blow or fall onto the shoulder. It’s common in contact sports and accidents. The injury can range from a mild sprain to a complete separation of the joint.

Common Causes Include:

Falling directly on the shoulder
Motorbike or bicycle accidents
Collisions in sports like rugby, football, or hockey
Heavy lifting accidents

Symptoms of AC Joint Dislocation

Sudden pain at the top of the shoulder
Swelling or bruising around the joint
A visible bump where the collarbone sticks up
Difficulty lifting the arm
A feeling of instability in the shoulder

How Is It Diagnosed?

A physical exam and X-ray are usually enough to confirm the diagnosis. Your doctor will check for tenderness and movement, and the X-ray can show how far the bones have moved out of place.

Imaging Tests:

X-Ray: Confirms dislocation and shows severity
MRI: Used if soft tissue injuries (like ligament tears) are suspected

Types of AC Joint Dislocation

Doctors classify AC joint injuries from Type I to Type VI based on how much damage there is:

Type I: Minor sprain, no dislocation
Type II: Partial dislocation, some ligament damage
Type III: Complete dislocation, collarbone raised
Types IV–VI: Rare and more severe dislocations needing surgery

Treatment Options

Non-Surgical Treatment

Most Type I and II injuries are treated without surgery.

Rest and a sling for support
Ice to reduce swelling
Pain relief medications
Physiotherapy to regain strength and motion

Surgical Treatment

Surgery may be needed for more severe dislocations (Types III–VI), especially in active individuals or athletes. The procedure may involve reconstructing the damaged ligaments and stabilizing the joint with a plate or suture loop.

Recovery and Rehabilitation

Recovery time depends on the type of injury and treatment:

Non-surgical recovery: 4–6 weeks for most daily activities
Post-surgery recovery: 3–6 months with physiotherapy

Physiotherapy is important to restore movement, reduce stiffness, and rebuild shoulder strength.

When to See a Doctor

See your doctor if you:

Feel a sudden pain in the top of your shoulder
Notice a bump or unusual shape in your shoulder
Have difficulty moving your arm or lifting objects

Can AC Joint Dislocation Be Prevented?

Use proper techniques in sports
Wear protective gear in contact sports
Strengthen your shoulder muscles
Be careful on uneven surfaces to avoid falls

AC Joint Dislocation (Acromioclavicular)