Background: Acetabular dysplasia is a congenital deformity that leads to hip osteoarthritis. The reason is the abnormal load transfer on the head which causes the cartilage damage and the progressive lateralization of the rotation centre of the head. The reorientation spherical periacetabular osteotomy, introduced by H. Wagner in 1976, has the aim to normalize the acetabular parameters increasing the coverage of the femoral head. The original indication of the author was the correction of the insufficient acetabulum in young adult patients, just after the closure of the triradiate cartilage, in which it is possible a functional adaptation of the osteotomized hip.
Materials and Results: This surgical procedure has been performed in the First Division of Galeazzi Orthopedic Institute of Milan Italy, since 1979 (180 cases up today).
The hips operated before 1985 were 14. The patients were 10, in 4 cases the operation was bilateral. There were 9 females and 1 male. The average age of the patients at the time of the operation was 19.3 years. All the patients had a DDH without X-ray signs of osteoarthritis and had a mild or absent pain. In 9 cases the isolated periacetabular osteotomy was performed and in 5 cases a femoral varus osteotomy was associated at the same time. The osteotomies were Wagner type I in 12 cases and Wagner type III in 2 cases.
We always used a Smith-Petersen approach. The periacetabular osteotomy was made by special spherical chisels of different diameter under X-rays control. The fixation of the osteotomy was made in 8 cases according to the original technique with a special double horn plate fixed by screws to the ileum and in 6 cases only with the help of Kirsches wires, as actually we prefer.
10 cases with a clinical and X-ray follow-up longer than 20 years have been controlled. 4 cases are lost to follow-up. Occurrence and type of pain, walking, limp, range of motion were evaluated. Wiberg CE angle, signs of osteoarthritis and centre of rotation of the head are observed on the X-rays.
Discussion: Evaluating the results, natural history of DDH must be considered. The revision of long term results (follow-up longer than 20 years) shows that it is possible to obtain good clinical outcome in the prevention of arthritis and on patients’ symptoms. The indication must be strictly followed: full indication is maintained in dysplasia of the adolescent, indication in the young adult only if some symptoms are present, very rare indication in patients with signs of arthritis and only in very mild cases. As a matter of fact in a group of patients with a shorter follow-up that is not part of this study, in which the indication was extended to Tonnis 1–2 arthritis we had much more bad results and complication. We observed generally worst results with obese patients.
