Developmental dysplasia of the hip in Marfan syndrome.

Among 235 consecutive patients with Marfan syndrome, four cases of developmental dysplasia of the hip were found, amounting to an incidence of 2%. Harness treatment was not effective in any of the patients because of a narrow stable zone and knee laxity. One patient died of cardiac failure before further treatment could be attempted. Closed reduction and spica cast treatment was successful in all other patients. Stability was achieved within a normal period, and there were no redislocations. Consequently, the dislocated hip in patients with Marfan syndrome should be managed early with this method.