A spherical rotational osteotomy performed close to the acetabulum to correct acetabular dysplasia in adolescents and young adult patients was described by Wagner in 1965. Since 1980, we have used the anterior surgical approach of Smith-Petersen and special spherical chisels as our operative technique. Stable internal fixation with modified semitubular plates allows early functional postoperative treatment without external immobilization. Adherence to strict surgical indications has yielded good results with few complications and infrequent need for revision surgery. Results from three series of spherical osteotomies (>300 hips) validate the concept of major acetabular redirection for improvement of prognosis in adolescents and young adult patients with moderate and severe congruous acetabular dysplasia.