OSTEOCHONDROSIS

also called epiphyseal ischemic necrosis poorly understood but relatively common orthopedic disorder of children in which the epiphysis (growing end) of a bone dies and then is gradually replaced over a period of years. The immediate cause of bone death is loss of blood supply, but why the latter occurs remains unclear. The most common form, coxa plana, or Legg-Calv-Perthes syndrome, affects the hip and most often begins about the age of six. It is four times more frequent in boys than in girls. Crippling may result, and degenerative joint disease is a complication of middle age. Treatment is directed first toward protection of the part from injury, together with rest and immobilization. In severe cases, detached fragments from the joint are removed by surgery.