We reviewed radiographs of 22 hips in 22 children treated by Pemberton and Salter osteotomies for acetabular dysplasia. The average age of patients at operation was 4 years 5 months. We measured changes in AC and center-edge angles and lateralization of the acetabular fragment on the medial side of the osteotomy. In both procedures, good lateralization was very important to the final growth of the acetabulum. Analysis of results showed that good containment of the femoral head was achieved only when the position of the outer edge of the acetabulum was changed so that it was beyond the point of maximal pressure of the femoral head, preventing pressure on the acetabular growth zone.