Rotator cuff disease can be divided into 3 stages. The first stage includes subacromial impingement syndrome, bursitis or a tendinopathy. The next stage is a partial rotator cuff tear. The last stage is a full thickness rotator cuff tear, which can progress to a rotator cuff arthropathy.
The causes of rotator cuff disease have not been determined; one of the hypotheses is that a combination of intrinsic and extrinsic factors may be the cause. Sometimes the cause can be traumatic, however in elderly people this is not necessarily the case.