Avascular necrosis after nonoperative treatment of developmental hip dislocation. Prognosis in 36 patients followed 17-26 years.

36 children (61 hips) who had nonoperative treatment of developmental hip dislocation with the Frejka pillow and developed avascular necrosis were followed-up for an average of 20 (17-26) years. The radiographic pattern of necrosis was classified into 5 types. At final follow-up after completion of growth, the radiographic outcome was excellent in 11 hips, good in 21, fair in 19, and poor in 10 hips. There was a close correlation between the pattern of necrosis and the outcome: all the poor results were observed in cases with changes also involving the metaphysis.