Kashin-Beck disease

**Definition:** Kashin-Beck disease (KBD) is a chronic, endemic osteochondropathy of unknown etiology. The disease is mainly distributed in a diagonal belt ranging from the northeast to the southwest of China, where the soil selenium content is low. Mineral deficiencies (e.g., selenium, iodine), fungal cereal contamination, and water contamination may be contributing factors to its etiology. The disease is manifested by arthritic pain, morning stiffness, enlarged and shortened fingers, deformed and enlarged joints, and limited motion of the joints in the extremities.