AC joint injury - initial postoperative program

The shoulder region is a compound of 4 bones, connected together at different locations in the shoulder (scapula, humerus, clavicle and sternum) and it has a series of ligamentary and musculo-tendon structures. One of the shoulder joints is the acromioclavicular joint (articulatio acromioclaviculare, AC) connecting the highest part of the shoulder, the acromion on the scapula and the clavicle at its lateral part.

The AC joint is passively stabilized by 3 ligaments, lig. acromioclaviculare, lig. coracoclaviculare and lig. coracoacromiale. Inuries to the AC joint can happen on either the bones, ligaments or tendons of said region, ie. there can be a bone fracture, joint luxation, ligament/tendon strain or tear and in some cases even the surrounding blood vessels and nerve tissue can get damaged.

The most common injury mechanism is during the impact of direct external force on the AC joint, during falls or blows, eg. falls from a bicycle or motorcycle, car crashes, falling directly on the tip of the shoulder with the arm tucked close to the body, falling on an extended arm, hits to the upper part of the shoulder. AC injuries are common in rugby, ice hockey, skiing, cycling, judo, etc.

Most common degrees/types of AC joint injuries:

1. Strain and partial rupture of joint capsule, ligaments remain intact

2. Strain of the acromioclavicular ligament with the coracoclavicular ligament intact

3. Ruptured acromioclavicular and coracoclavicular ligament.

Symptoms include a sharp and very intense pain, swelling and hematoma at the location of injury, ie. top of the shoulder, the shoulder can fall forward due to loss of support from the AC joint, inability to perform movements in the shoulder joint, external tip of the clavicle can be tipped upwards, etc.

Tretment can be either conservative or surgical, depending on the severity of the injury. With more difficult or combined injuries a surgical approach is implemented and with less severe injuries a conservative approach is used, the shoulder is immobilised in order to let the bones and ligaments heal properly and in a timely manner. After the healing process is finished functional therapy is used to regain shoulder range of motion and full mobility, to develop strenght in all shoulder muscles, especially rotatory cuff muscles and to regain AC  and shoulder joint stability.