Acomioclavicular Joint (AC joint) Injuries

The acromioclavicular (AC) joint is at the top of the shoulder between the collarbone and shoulder blade and is stabilised by many ligaments. It is essential for overhead and across body movement of the arm as well as pushing, pulling and lifting movements.

An acromioclavicular joint injury is often referred to as shoulder separation, and must not be confused with shoulder dislocation.


An acromioclavicular joint (AC) injury can be caused by the ligaments supporting the acromioclavicular joint becoming overstretched. The AC joint ligament damage that patients experience can vary from a mild ligament strain to complete ligament tears and deformity.

The acromioclavicular joint can also be injured by falling with an outstretched arm or a collision, which is why it’s more common in athletes and older patients. It is also a common injury sustained when landing on your shoulder from falling off a bicycle or mountain bike


An acromioclavicular ligament sprain can be indicated by a pain on the top of the shoulder, which is made worse by lifting heavy items or moving the arm overhead or across the body. Symptoms also include swelling and bruising, or a hard visible lump on top of the shoulder, which would indicate a displacement of the collarbone.


Following an X-ray to determine that there is no fracture, most patients feel better following a few days of rest and by using a sling, tape or shoulder brace. However, full ligament healing can take up to 10 to 12 weeks.

In some cases, surgery is required repair the AC joint. Following surgery, you will be in a sling for around 2 weeks with postoperative physiotherapy to restore full shoulder motion and strength.


Acomioclavicular Joint

(AC joint) Injuries

Frozen Shoulder

(Adhesive Capsulitis)

Shoulder Dislocation

and Instability

Rotator Cuff

Problems of the shoulder

Shoulder Replacement


Calcific Tendonitis

(shoulder tendons)

Fractures of the shoulder

Proximal humerus & scapula

Shoulder Impingement

(Rotator Cuff)