Rupture of the acromial-clavicular joint with dislocation of the acromial end of the clavicle

This injury is common in young patients involved in contact and throwing sports, accounting for up to 40% of all sports shoulder injuries.

At the moment of injury, the clavicular-acromial ligament ruptures (with incomplete damage) and the clavicular-clavicular ligaments are completely damaged. As a result, the clavicle is displaced upward, and with an incomplete rupture, instability occurs in the clavicular-acromial joint.  The mechanism of injury is a fall on the shoulder, elbow, or outstretched arm.

Immediately after the injury, there is a sharp pain in the upper arm, swelling of the soft tissues and bruising in the projection of the acromial end of the clavicle. Movement in the shoulder joint is limited due to pain, and the patient can support the injured limb with his healthy arm. On examination, a deformity becomes noticeable – a step between the acromion and the collarbone. Palpation determines the symptom of a "key" when pressing on the collarbone.

A definitive diagnosis can be made by radiography. In doubtful cases, it is advisable to perform radiography with a load – during the examination, the patient holds a load weighing 0.5-1 kg. An upward displacement of the clavicle compared to the healthy side indicates a complete rupture of the ligaments of the acromioclavicular joint.

First aid includes: local cold, kerchief bandage, painkillers. In cases with incomplete ligament damage, rest of the limb is further indicated with a gradual development of movements over 2-3 weeks. With a complete rupture of the acromioclavicular joint, surgical intervention is indicated.

In case of refusal of surgical intervention with complete damage, except for a cosmetic defect, due to instability in the clavicular-acromial joint, rapid development of osteoarthritis with severe pain syndrome and involvement of surrounding anatomical structures is possible.