Etiology of osteochondroses is typically unknown; some of the disorders have a familial component, but inheritance is complex. Osteochondroses differ in their anatomic distribution, course, and prognosis; they typically cause pain and have important orthopedic implications. Common examples include
Rare osteochondroses and the involved bones include Freiberg disease (head of 2nd metatarsal), Panner disease (capitulum), and Blount disease (proximal tibia). Sever disease (calcaneal apophysitis) is a more common osteochondrosis.