The natural history of Perthes' disease.

Since 1975, none of our patients with Perthes' disease have received any active treatment, except for managing severe pain. We have studied the functional and radiological results in order to evaluate the consequences of this approach and to demonstrate the natural history of the disease. We have followed up all patients over the age of 19 years; out of 20 only 6 were free of pain and only 2 reached 100 points on the Iowa hip score. Radiographs at follow up demonstrated that no involved hip had a spherical femoral head. We conclude that our passive attitude towards Perthes' disease results in relatively few patients having good hip function, especially when compared with the results of other authors. Active treatment, including operation, is probably more successful.