The shoulder joint is the most mobile joints of the human body. Because of its range of movements, it is very unstable. To keep its stability, the shoulder is reinforced with muscles, tendons and ligaments. The key structure is the rotator cuff. It is made up of tendons and four muscles: subscapularis, supraspinatus, infraspinatus and teres minor. The humeral head is located on its lower part, and the acromioclavicular joint on its upper side. A functionally normal rotator cuff stabilizes the humeral head when making movements of the arm. By damaging one of the four rotator cuff muscles, loss of stability and clashing of the humerus with the neighboring bones and ligaments of the acromioclavicular joint can occur. This way the impeachment syndrome appears. The impingement syndrome is an inflammatory process on the appropriate part of the rotator cuff (tendinitis) which happens as a result of the repetitive and frequent „strangulation“ of the soft tissues between the humeral head and acromioclavicular arch above it. Long-term repetitive „strangulations“ cause degenerative changes of the rotator cuff (tendinosis), and after that partial or total rupture in the rotator cuff area. Because of its position and function, supraspinatus tendon gets damaged most frequently (90% of times).

Generally speaking, the cause of these conditions is a long-term activity with the arm raised above the head or frequent, but short and powerful activity with the raised arm. The most common sports associated with rotator cuff injury are handball, volleyball, swimming and water polo. The injury is associated with professions that require repetitive arm movements above the height of the shoulder such as: cleaner, mason, painter, car mechanic. Pre-disposing factor could be a poor shape of the acromioclavicular arch.

Regardless which injury to the rotator cuff is concerned, the fundamental problem is the inflammation and associated pain which gets worse with movement or by pressing of the soft tissue on the bone arch (e.g. when sleeping). Patients complain of shoulder pain, frequently on the outer side of the humerus, especially when doing activity above the shoulder height. Furthermore, weakness of the arm occurs along with pain. During the clinical examination, the diagnosis is confirmed by an ultrasound or magnetic resonance of the shoulder.

Patients who do not have greater difficulties and are older, do not need surgery. They are advised to avoid bigger loads during the day and to take nonsteroidal anti-inflammatory drugs. All other patients start with physical therapy. If their difficulties persist, in regard to the size and type of injury to the rotator cuff, different types of surgeries are advised. Open type surgeries are performed when there is a massive rupture of the rotator cuff and when and arthroscopic surgery is not possible. Postoperative course requires physical therapy and lasts for a few months. Full load on the arm is advised 4 to 6 months after the surgery.