AC Joints
What Is an Acromioclavicular (AC) Joint Injury?
The acromioclavicular (AC) joint — along with ligaments — connects your collarbone and shoulder blade.
An injury to the AC joint is a shoulder separation.
Types of AC joint injuries
The type of shoulder separation depends on how much you tear the AC joint or coracoclavicular (CC) ligaments that hold the joint in place.
- Type I = the AC ligament is slightly torn, but there's no damage to the CC ligament is unharmed.
- Type II = the AC ligament is completely torn, and there's little or no tear to the CC ligament.
- Type III = both the AC and CC ligaments are completely torn. In this case, the collarbone separates from the end of the shoulder blade.
- Three more types of AC joint injury are also possible, but rare. These involve tearing of the ligaments and surrounding muscle tissue.
Shoulder separation or AC joint injury causes
Shoulder separation often happens because of a hit too:
- The tip of your shoulder.
- The top part of your shoulder.
- Your outstretched arm.
- You may damage the AC joint or rotator cuff from a fall or tackle during a game.
AC joint injury symptoms
Shoulder separation may cause symptoms such as:
- Pain
- Limited motion in the shoulder
- Swelling
- Bruising
- Tenderness at the top of the shoulder
- You may also be able to see that the collarbone is out of place or notice a bump on the shoulder.
Acromioclavicular (AC) Joint Injury Treatment Goals and Options
The main goals of treatment for an AC joint injury are to manage pain and allow the torn ligaments to heal.
Type I or II AC joint injury treatment
Treatments for type I and II injuries include:
- Icing the shoulder.
- Put your arm in a sling to decrease motion.
- Take NSAIDs, like ibuprofen or naproxen, to help with the pain.
- You will need to wear the sling for a few days to a week or more depending on how severe the injury is.
You will need to begin physical therapy as soon as you can, and do minimal exercise with your arm to avoid a frozen shoulder.
Type III AC joint injury treatment
- Your doctor will decide the best course of treatment, based on the extent of damage to the joint.
- You may have to wear a sling and undergo physical therapy.
- In some cases, your doctor may suggest surgery to repair the torn ligaments.
