[Diseases of the acromioclavicular joint].

The acromioclavicular joint together with the sternoclavicular joint represents the only articulation between the shoulder girdle, the upper extremities and the trunk. The high load on the relative small joint surface results in a high risk for degenerative changes. The most common pathology is therefore osteoarthritis. In addition, joint instability and many inflammatory processes can occur, especially rheumatoid type pathologies and metabolic disorders. Acromioclavicular cysts represent a clinically evident disease, which are frequently associated with an underlying cuff tear arthropathy. A thorough clinical examination supported by appropriate imaging allows a rapid and reliable diagnosis. Conservative therapy is usually symptom related. Surgical procedures after failed conservative therapy must be specific for the pathology in question and are successful in most cases.