Background
The neglected developmental dysplasia of the hip with adaptive changes in bone and soft tissue is difficult to treat. Dega osteotomy is added to open reduction to confer concentric stable reduction with good coverage of the head of the femur.
Patients and methods
Forty hips in 32 patients were treated using open reduction and Dega osteotomy. There were 30 dislocated and 10 subluxated hips according to Tonnis grading. Radiographic parameters used in this study included the acetabular index, the acetabular angle of sharp, the caput-collum-diaphyseal angle, and the center-edge angle of Wiberg; the final radiographic outcome was evaluated according to the Severin classification. Clinical results were evaluated according to the modified McKay criteria.
Results
The mean follow-up period was 96 months. The final results according to Barrett’s modification of McKay’s criteria were as follows: 34 (85%) with favorable results and 6 (15%) hips with unfavorable results. According to the Severin criteria for the evaluation of radiographic results, 74% were types I and II whereas 26% showed types III and IV; no hips were rated as Severin’s groups V or VI. Eight (33.4%) hips in children with unilateral involvement had developed coxa magna, but in no case did this interfere with hip concentricity. Three hips showed avascular necrosis on the latest radiographs.
Conclusion
The Dega osteotomy added to the open reduction, capsulorrhaphy, and femoral shortening is a safe, simple, and adequate procedure for the management of neglected developmental dysplasia of the hip patients after 2 years of age, with lower complication rates. Restoring the acetabulum to normal or nearly normal can result in good long-term results.