Partial cuff tears are a well known entity in shoulder pathology. They occur both in young athletes, when the shoulder is subjected to high loads in extreme positions, as well as in older people, with degeneration as the main cause. Although the diagnosis is presently made more frequently, there is still a lot of discussion on classification, pathophysiology, diagnostic and treatment modalities. This symposium will bring together all new data on pathophysiology and inform the participant on the best way to diagnose this entity. The ISAKOS Upper Extremity Committee has considered it as its task to introduce an updated classification, which will be discussed during this session. Best evidence will also be pursued during the lecture on treatment of partial cuff tears. At the end of this symposium the participant is updated on the best evidence available for this intriguing disease.