Perthes' Disease

1 . Thirty-four cases of Perthes' disease followed into adult life were reviewed twenty-five to forty years (average thirty years) after diagnosis. 2. Rather more than one-third of the patients developed hips which were good, an equal number were considered fair and about one-quarter were poor. 3. Four out of five patients were fully active and free from pain but only two out of five had hips which were radiologically good. 4. Clinical and/or radiological deterioration had seldom occurred in the last twelve years. 5. A good result in childhood is likely to be maintained with no pain and good function up to the age of forty years and perhaps longer.