Dega osteotomy for the treatment of congenital dysplasia of the hip

Background: In 1969 Dega described a transiliac osteotomy to treat residual acetabular dysplasia secondary to congenital hip dysplasia or dislocation. We were unable to find a thorough description of the technique in the Engl ish-language orthopaedic literature, and the number of clinical follow-up s eries is small. Methods: Twenty-two children (twenty-four hips) with an average age of five years and ten months and varying degrees of congenital hip dysplasia, subl uxation, or dislocation were treated with a Dega osteotomy. Twenty hips (83 %) had a concomitant femoral osteotomy and thirteen (54%) had an anterior o pen reduction of the hip in addition to the Dega osteotomy. To be included in the study group, each patient had to have complete clinical documentatio n of the range of motion, presence or absence of a limp, limb-length discre pancy, hip pain, and limitation of activity. Radiographs were reviewed to d etermine the acetabular index, the center-edge angle, whether the Shenton l ine was intact or broken, and any change in the projection of the obturator foramen. Results: At an average of fifty-five months postoperatively, all patients d emonstrated unlimited physical activity and no limp. The average acetabular index changed from 33 degrees preoperatively to 12 degrees at the time of follow-up. The center-edge angle ranged from less than -30 degrees to 18 de grees preoperatively and from 18 degrees to 40 degrees (average, 31 degrees ) at the time of follow-up. A change in the obturator foramen was observed in fourteen hips (58%). The Shenton line was broken in seventeen hips preop eratively but in none postoperatively. One Dega osteotomy was revised immed iately after the index operation, and three hips underwent late repeat corr ection of the proximal part of the femur; one of the repeat corrections was performed together with a repeat Dega osteotomy. Conclusions: Our initial experience with the Dega osteotomy demonstrated it to be a valuable surgical treatment of congenital dysplasia of the hip in a child of walking age. Our experience is comparable with that of many Euro pean authors, including those reporting studies from Dega's own institution .