Chondropathy refers to diseases of the cartilage that are graded from 0-4, with 0-2 being normal and 3-4 being diseased. Some common diseases involving cartilage are osteoarthritis, which causes thinning and wearing of articular cartilage in joints; achondroplasia, which causes dwarfism from reduced cartilage growth; and costochondritis, which is inflammation of rib cartilage causing chest pain. Osteochondrosis is a term for disorders affecting the growing skeleton from abnormal growth, injury, or overuse of growth plates.