For the treatment of the acetabular dysplasia in the early childhood the spherical periacetabular osteotomy of the ilium is a well-recognized procedure.

52 hips of 35 patients treated with a periacetabular osteotomy between 1969 and 1985 we followed-up after 14 to 31 years. At the time of operation the average age was 2,8 years.

The measurement of the anterio-posterior radiographs showed a normalization of the acetabular roof obliquity in 79% of the cases. However, there were only 46% of the cases with a normal center-edge angle. 42% had a medium pathologic angle of 20 to 30 °. In 12 % we saw severe pathology with angles smaller than 20.

Fife cases (10%) presented radiologic signs of osteoarthritis and three a slight incongruence between head and acetabulum.

Rare cases of postoperative complications are presented.

The low incidence of radiographic osteoarthritis supports the view that the spherical periacetabular osteotomy is an appropriate surgical procedure to treat acetabular dysplasia in early childhood.