Abstract
1. A rationale of subtrochanteric osteotomy with derotation and varus angulation in the treatment of Perthes' disease is suggested.
2. Three months after operation the child returns to a normal unrestricted life.
3. The anatomical results in twelve such operations with an average follow-up of two years and five months are presented. In five children the results were "very good," in four "good," in one "fair" and in one "bad."
4. These results seem to compare favourably with those observed after conservative treatment of two, three or more years duration.