The acromioclavicular joint, often known as the AC joint, is a joint in the shoulder where bones converge. The clavicle or collarbone is one of the bones. The AC joint helps an individual’s range of motion as he/she raises the arm above the head. Therefore, the range of motion in the arm can be limited if the joint becomes sore or inflamed.

Types of AC Joint Injuries

• Type I: Here the AC ligament is slightly torn; but the CC ligament is not damaged
• Type II: The AC ligament is completely torn but the CC shows little or no strain
• Type III: The ligaments in the AC and CC are totally torn. In this case, the collarbone and shoulder blade’s tip separate.

Causes of AC Joint Injury

AC joint injuries frequently result from a blow or hit to:

• The tip of the shoulder
• The top part of the shoulder
• Outstretched arm

Symptoms of AC Joint Injury

Symptoms of AC injuries often get worse when performing certain activities, such as lifting objects above the head or crossing arms.

They usually include:

• Pain
• Limited motion in the shoulder
• Swelling
• Bruising
• Tenderness at the top of the shoulder

Risk Factors of AC Injuries

• Having a history of a traumatic shoulder injury
• Manual work
• A job that requires heavy lifting
• Inflammatory arthritis
• Being above 50 years in age
• Sports such as weightlifting, basketball, or swimming can cause repetitive harm to an individual

Diagnosis of AC Joint Injury

The doctor will conduct an exam to look for symptoms of an AC joint injury. He/she will look at:

• Muscle strength
• Blood flow
• Signs of a broken shoulder or damage to the rotator cuff

An X-ray may be recommended on the shoulder to see the severity of the damage and confirm the collarbone isn’t fractured.

Treatment of AC Joint Injuries

Type I and II AC joint injuries

Doctors recommend the following treatment options for type I and II AC injuries:

• Icing the shoulder
• Immobilizing the arm in a sling to decrease motion
• Using NSAIDs to treat pain

Depending on how severe the injury is, the patient will need to wear the sling for a few days to a week or even more. Physical therapy is recommended as soon as possible. The patient should engage in minimal exercises to avoid a frozen shoulder.

Type III AC joint injuries

The treatment team will decide the most suitable treatment option, based on the extent of damage to the joint. The patient may be required to wear a sling and undergo physical therapy. In some instances, the doctor could recommend surgery to fix the torn ligaments.