Final answer:
Hydroxyapatite Deposition Disease (HADD) is a condition that primarily affects the shoulder joint, characterized by the formation of calcifications near the insertion of a bursa or tendon. It is caused by the deposition of mineral salts, primarily hydroxyapatite, on the collagen matrix.
Step-by-step explanation:
Hydroxyapatite Deposition Disease (HADD), also known as calcific tendinitis or calcific periarthritis, is a condition that primarily affects the shoulder joint. It is characterized by the formation of round or oval calcifications near the insertion of a bursa or tendon. The mineral salts primarily involved in HADD include hydroxyapatite, which is formed from calcium phosphate. Calcification occurs when mineral salts are deposited on the collagen matrix and crystallize on the tissues.