Comparison of open reduction alone and open reduction plus Dega osteotomy in developmental dysplasia of the hip

In the treatment of developmental dysplasia of the hip, concentric reduction of the femoral head into the acetabular cavity plays a key role in the natural development of the acetabulum. However, there is still debate on the need for additional acetabular osteotomies and their timing. In this study, we compared open reduction (OR) alone with OR plus Dega osteotomy for acetabular index (AI) development. Twenty patients, 10 in each group, who underwent either OR alone or OR plus Dega osteotomy were studied retrospectively. All patients were diagnosed with developmental dysplasia of the hip and none of them received treatment previously. Preoperative, early postoperative, and follow-up radiographs were gathered, radiological grading was performed according to Tönnis, and AI angles were measured. The OR group had a mean age of 24.5 months, whereas the Dega group had a mean age of 24.8 months. The mean follow-up period of the OR group and Dega group was 57.8 and 66.6 months, respectively. In the OR group, the initial mean AI was 37.5° whereas in the Dega group it was 46°. After the follow-up, despite the acetabular development in the OR group being twice as fast, the final mean AI was 25.5, whereas it was 15.9 in the Dega group. The difference was statistically significant (P<0.05). Using Tönnis' definition, the Dega group ended up with 70% normal hips, 20% mild dysplasia, and 10% severe dysplasia, whereas the OR group had 20% normal hips, 30% mild dysplasia, and 50% severe dysplasia at the final visit. There was no correlation between the initial radiological grading of dislocation and the final result. OR plus Dega osteotomy is a good option to regain acetabular coverage over the femoral head. It provides better radiographic results after a 5-year follow-up period in patients with a mean age of 25 months. OR alone should not be performed unless the child had mildly dysplastic acetabulum according to Tönnis' definition.