Dega Osteotomy for the Treatment of Developmental Dysplasia of the Hip, a Clinical Evaluation and an Anatomic Study based on X-ray and CT Scan.

Abstract

Dega osteotomy is becoming more widely used for the treatment of developmental dysplasia of the hip (DDH). A thorough description of this procedure is needed as many of the technical aspects are not fully defined. Moreover, more follow-up series are also needed to evaluate its outcomes. In this study, we gave a detailed anatomic description for this procedure and also presented our experience as a retrospective radiographic and case-note study. We examined the clinical and radiographic records of 44 patients (48 hips) with varying degrees of DDH. The average age of the patients was 2 months and 7 months while the average follow up period was 41 months. Clinical and radiographic assessment including CT with 3D reconstruction to examine the anatomic characteristics of the osteotomy were undertaken. We found that concentric reduction was achieved in 93.7% with excellent clinical and radiographic outcomes. Only 3 cases needed revision of the Dega osteotomy. The re-operation rate was 12.5%. CT scan revealed that the arcuate line was crossed by the osteotomy in the majority of cases. In 20.7% of cases, a bone cut that was intended to be a Dega osteotomy was found to have been inadvertently implemented as another osteotomy variant. However, this bore no significant effect on the outcome. We found that a well-implemented Dega osteotomy is a reliable tool to cope with the acetabular changes in DDH.