<unk>  is caused by deposits of calcium phosphate crystals in the tendons of the shoulder. These deposits are most frequently found in the supraspinatus tendon (63% of the time), and less frequently in the infraspinatus tendon (7%), subacromial bursa (7%), subscapularis tendon (3%), or in both the supraspinatus and subscapularis tendons at the same time (20%). The development of<unk>  is often divided into three stages. First, in the "precalcific stage", something causes tendon cells to transform into other cells that can act as sites for calcium deposition. This is followed by the two-part<unk>  stage"; first calcium is deposited (the formative phase), then the body begins to break down the calcium deposit (the resporptive phase). Finally, in the "postcalcific stage" the calcium deposits are replaced with new tissue and the tendon completely heals. The cause of the calcium deposits remains unclear, although several theories have been put forward. Some theories involve the differentiation of tendon cells into other cells, namely cartilages or bone cells. Others associate the condition with cell death due to aging, wear, or lack of oxygen in the tissue; however, the disease is uncommon in the very old, not associated with exercise, and tends to resolve completely even if untreated.
Calcific tendinitis
Retrocalcaneal bursitis
Ischial bursitis
Pes anserine bursitis
Infrapatellar bursitis
Facet joint arthrosis
Subacromial bursitis
Olecranon bursitis