Acromioclavicular Joint Dislocation

Anatomy And Pathology

The Acromioclavicular joint is  formed between the Collar bone (Clavicle)  and the Acromion (top of the shoulder blade). The joint has a lining cartilage and a disc of cartilage.

Injury to the joint classically occurs with a fall on to the point of the shoulder. Injury can be a simple strain or  a complete separation / dislocation of the joint.

Symptoms

Patients are often  not disabled long term. Many return to all activities. A smaller percentage complain of late pain, clicking / grinding and instability that is localised to the region of the Acromioclavicular joint. If this occurs then reconstruction of the Acromioclavicular joint is sometimes indicated.

Surgery

The goal of surgery is to

1. Reduce the collar bone / clavicle back down into its anatomic position and
2. Reconstruct the torn Coracoclavicular ligaments that hold it in position.

To do this a Hamstring tendon is harvested from your leg via a small incision. This tendon utilised to reconstruct the coracoclavicular ligaments. It  is  looped under a knuckle shaped bone the coracoid and secured to the clavicle via 2 holes in the clavicle. Small interference screws hold the tendon in position as the tendon heals in position.

Complications

These include infection and recurrent instability. The operation is generally successful in 80-90 % of patients.