Acromioclavicular joint separation

Regaining a stable shoulder

Sporty people are familiar with it: Take a fall over your bicycle handlebars or fail to notice an icy patch on the slope and you actually take the fall quite well. Nevertheless, your shoulder hurts. All this can indicate an acromioclavicular joint separation (AC separation).

At Schoen Clinic, we specialise in the treatment of acromioclavicular joint separation. Based on a detailed diagnosis, we offer you the optimal treatment for you. We help you to fully restore the mobility of your shoulder. 

Causes & symptoms

What do we understand by AC separation?

The acromioclavicular joint (AC joint) is located at the upper outer part of the shoulder. It is formed by the collarbone (clavicle) and the acromion. The collarbone is the only bony connection to the shoulder. It is therefore very important for the stability of the shoulder. The AC joint is protected horizontally and vertically from external influences by muscles and ligaments. In acromioclavicular joint separation, the acromioclavicular joint is completely or incompletely dislocated by traumatic external influences (luxation).

AC separation: Causes of this injury

Acromioclavicular joint separation is a frequent injury that mostly affects people who are active in sports. Men are affected five times more frequently than women. 

Falls onto the shoulder with an outstretched arm or road traffic accidents are typical causes. If AC separation is detected too late or not treated correctly, this can lead to persistent complaints in the shoulder area as well as in the neck muscles. This results in a significant reduction of the shoulder’s ability to work under pressure. This makes it all the more important to consult a shoulder specialist in good time after a corresponding accident. 

AC separation: Symptoms

Acromioclavicular joint separation often manifests itself in the immediate onset of severe pain. Those affected adopt a relieving posture, as movement aggravates the pain. The injured area is also very sensitive to pressure. 

As a result of the injury, swelling occurs above the AC joint. Abrasions often occur over the shoulder blade. Depending on the severity of the acromioclavicular joint separation, the collarbone may shift. This is then perceived as a “bump” over the shoulder. 

Diagnostics

Diagnosis: This is how AC separation is detected

At Schoen Clinic, we clarify in detail whether you actually have an acromioclavicular joint separation. To do this, our specialists first enquire about the cause of the accident. This is followed by a physical examination. If your collarbone has shifted, this is a clear sign of AC separation. For further diagnosis, we take X-rays of your acromioclavicular joint. 

Severity of AC separation

The degrees of severity of acromioclavicular joint separation are divided into six levels according to Rockwood. The correct treatment depends on the severity of the injury and your individual physical and athletic requirements. 


Rockwood I: The shoulder ligaments are strained, but not torn. The treatment is conservative.

Rockwood II: One of the ligaments that stabilises the shoulder and the articular capsule are torn, but the muscles are intact. We recommend conservative treatment. 

Rockwood III: Both ligaments are torn and the collarbone is high. We decide here which is the best treatment on an individual basis. In most cases, surgical treatment is not necessary.

Rockwood IV: Those affected show the signs of Rockwood III as well as a horizontally fixed displacement of the collarbone. Surgical treatment is necessary here.

Rockwood V: There is a tear of all stabilising ligaments of the acromioclavicular joint. In addition, there is a pronounced elevation of the collarbone. Surgical treatment is recommended in most cases.

Rockwood VI: Very rare injury in which the collarbone is shifted below another process of the shoulder blade. Surgical treatment is performed.