Acromioclavicular Dislocation: Causes, Signs, Symptoms, Diagnosis and Treatment

We talk about one of the shoulder joints. This injury occurs when a bone, which is part of the joint, exits, causing pain and functional disability.

Causes of acromioclavicular dislocation

The most common mechanism of the dislocation of the acromioclavicular joint is the fall, in which there is a direct force on the lateral side of the shoulder, which is usually in the position of abduction.

Sports injuries are the most common cause of dislocation of the acromioclavicular joint, specifically cycling, soccer, basketball and skates.

Among these sports activities, cycling is the most common and this occurs due to the direct impact on the joint when the arm is adducted or stretched, making the acromioclavicular joint more susceptible.

In addition to sports, there are other causes identified and in decreasing order of incidence that are traffic accidents, accidental falls and work-related injuries.

When it comes to accidents on the road, safety belts clenched in vehicles can aggravate the direct trauma to the shoulder.

Signs and symptoms

Symptoms of dislocation of the acromioclavicular joint range from minor discomfort with minimal activity to full disability of the injured shoulder.

In the acute form, patients may present pain, decreased range of motion or loss of strength in the affected shoulder.

The pain occurs when the patient makes high movements or lies on the affected side.

At first, the pain is diffuse and difficult to locate, but at a later stage, the patient can identify the location of the pain.

There may be swelling, deformity, ecchymosis in the injured area and joint restrictions in the rotation with marked sensitivity of the paraspinals in the surrounding cervicothoracic region.

You can also hear a click in the elbow. In addition, there may be local sensitivity.

Macroscopic deformity can be observed in the lesions due to dislocation and displacement of the skin.

Diagnosis of acromioclavicular dislocation

To diagnose joint pain, several orthopedic exams can be performed, such as:

Arm fall (while the patient is in the arm at 90 ° of abduction, the patient slowly lowers the arm), the Neer test, spring test, cross-test, groove test, compression test and the Kemp test of the cervical spine, which causes pain in the cervicothoracic junction.

Some patients may have a stiff shoulder due to a concomitant rotator cuff injury or other muscles.

In chronic presentation, persistent medial scapular pain is the most common complaint. Irradiated pain and brachialgia can also occur. This is due to the alteration of the scapulo-thoracic rhythm. If there is joint synovitis, the cross adduction test is positive.

The structures most commonly affected are ruptures of the articular side of the anterosuperior rotator cuff, pathologies of the long head of the biceps and upper anteroposterior lesions of the labrum, partial tears of the subscapular tendon of the articular side.

Among the differential diagnoses are: acromioclavicular sprain, distal clavicular fracture, osteolysis of the distal clavicle.


After the diagnosis of dislocation of the acromioclavicular joint, first aid must be established by applying ice. The shoulder should be immobilized with a sling of the arm.

The treatment approach for arm sling dislocation depends on the degree of injury or the degree of dislocation.

Grade I and grade II injuries are best treated conservatively, which means surgery is not required for full recovery.

Immobilization for a period of three to six weeks, followed by rehabilitation exercises can restore the initial function two or three months after the injury. Very often, there is no residual cosmetic deformity in grades I and II injuries.

The optimal treatment for acromioclavicular dislocation of grade III remains inconclusive. Currently, there are a multitude of treatment options available, but the final decision depends on the preferences of the surgeon.

For grades IV, V and VI, which are considered high grade, the treatment is usually surgical.

In patients with persistent symptoms and lack of return to initial function, surgery may be offered.

The specific surgical technique in dislocation of the acromioclavicular joint varies, from the primary repair of the coracoclavicular ligaments, the increase with autogenous tissue, the increase with absorbable and inadmissible sutures and other prosthetic materials and the coracoclavicular stabilization with metallic screws.

Rehabilitation plays a very important role in dislocation of the acromioclavicular joint.

Minimal immobilization and immediate initiation of rehabilitation are recommended to reduce pain and inflammation.

Advanced strengthening exercises can only be done after the scapular control has already been achieved.