Purpose of the study: The presentation of our results of surgical treatment of the hip joints affected by multiple epiphyseal dysplasia, using the Steel technique of triple osteotomy of the innominate bone in children.
Material: Twelve hip joints in 11 patients were treated by the Steel technique of triple osteotomy of the innominate bone at our department in the period from 2000 to 2001. However, the evaluation involved only children who also had multiple epiphyseal dysplasia, i.e., two boys and one girl. One of the boys had bilateral surgery with 6.5 months between the operations. The average age at the time of operation was 7.5 years, with a range of 6.5 to 8.5 years. The indication for the Steel osteotomy included severe conditions characterized by flattening and fragmentation of the proximal femoral epiphysis that was insufficiently covered by a dysplastic acetabulum.
Methods: The clinical evaluation was based on a classification system according to Merle d'Aubigné and Postel. Assessment was made on X-ray films before and after surgery. The follow-up was 17 to 29 months with an average of 2 years.
Results: The average Merle d'Aubigné and Postel score for the operated-on hips was 17.5 points. The maximum attainable value is 18 points; therefore all hips showed excellent clinical outcomes. Radiological examination showed an improvement in Wiberg's center-edge (CE) angle, i.e., from 15 degrees preoperatively to 44 degrees postoperatively (range, 10 to 25 and 41 to 48 degrees, respectively). The surgical treatment resulted in an average increase in the CE angle by 29 degrees, with the range between 21 and 33 degrees according to correction extent.
Discussion: A comparison of our results with those of other authors was not possible since no literature data were available on the Steel osteotomy in patients with multiple epiphyseal dysplasia. In our opinion these children constitute a specific category of patients with this disorder but the size of our group was too small to draw conclusions with a more general validity.
Conclusions: The Steel triple osteotomy of the innominate bone permits correction of abnormal anatomical conditions of hip joints in severe multiple epiphyseal dysplasia. The nature of this disorder, however, requires a long-term follow-up of the patients treated.