AC Joint Injuries

What is the AC Joint?

The acromioclavicular (AC) joint is where the clavicle (collarbone) meets the acromion (part of the shoulder blade). The joint is held by multiple ligaments (bands of fibers that connect bone to bone). These ligaments include the coracoclavicular (CC) ligaments, coracoacromial (CA) ligament, and the AC joint capsule.

The ligaments of the acromioclavicular joint.

What happens when you injure this joint?

An injury to the acromioclavicular (AC) is commonly known as a separated shoulder. This is normally caused by direct trauma to the shoulder, such as a hard fall or a direct force during sports. These types of injuries can vary in severity from a sprain to a full separation of ligaments. The severity is shown below in a “graded system.”

The mechanism of injury.

Rockwood Acromioclavicular Joint injury classification.

What are the symptoms of an AC joint injury?

The main symptom of an AC joint injury is pain at the joint itself. This is typically felt on top of the shoulder. Depending on the severity, there can also be a visible “bump” to the shoulder, bruising, a popping sensation, and swelling. The main role of the AC joint is to contribute to stability of the scapula and the shoulder girdle.

How is this diagnosed?

Dr. Zahab Ahsan and Sincer Jacob have extensive experience in diagnosing AC joint injuries. You can expect to have a physical examination, x-rays, and possibly an MRI if indicated to assess the extent of the ligament injury and ensure there is no shoulder fracture. In some instances, the trauma from an AC separation leads to an injury to the glenoid labrum as well, this can be diagnosed on MRI imaging.

Left-sided Rockwood type V AC joint dislocation seen in the (A) unweighted panorama view, (B) anteroposterior view, and (C) axillary view.

What is the treatment?

Treatment of an AC joint injury is dependent on the severity of the injury. We think broadly in our approach (non-surgical vs. surgical).

Non-Surgical

In low-grade AC joint injuries, a customized treatment plan will likely entail rest, stabilization in a shoulder sling, anti-inflammatory medications, and a physical therapy program. The combination of these items leads to a decrease in AC joint pain in many cases. In most cases, patients are able to return to all activities within 1-6 weeks. Occasionally, a steroid and toradol injection into the AC joint can be helpful in reducing pain and inflammation to aid in non-surgical treatment.

Surgical

In more severe cases, a customized surgical approach may be recommended by Dr. Zahab Ahsan and Sincer Jacob. This decision is reached based on patient goals. Dr. Zahab Ahsan commonly uses arthroscopic assisted AC joint stabilization to stabilize the AC joint and correct the separation of the clavicle and acromion. The surgery includes small incisions, a camera, and special surgical instruments resulting in a less-invasive surgery and an accelerated recovery time. The joint is typically reconstructed using a ligament graft and sutures to restore stability and return the patient’s function. Surgery results are most effective and successful when patients follow a rehabilitation protocol provided by our team.

If you have any questions regarding an AC joint injury or AC joint pain, please contact Dr. Zahab Ahsan or Sincer Jacob.