 Rotator cuff tears are one of the most common causes of shoulder pain. Evidence-based guidance on optimal diagnostic and treatment strategies for rotator cuff tears is lacking. Our proposed study aims to fill these gaps by identifying the prognostic factors which will predict better outcomes of rotator cuff tears, based on both operative and non-operative treatment. The investigators will also compare outcomes of operative and non-operative treatment of rotator cuff tears and report on the best way to diagnose rotator cuff tears. 