A Study on the Incidence of Avascular Necrosis Following Closed Reduction of the Dislocated Hip in Children with Congenital Dysplasia of the Hip: a Suggestion on Clinical Management

Abstract

Background: Our district general hospital is one of two providers of elective paediatric orthopaedic services to a rural population with an annual live birth rate of approximately 5000 per year. The preferred practice in our hospital for dislocated hips in cases of congenital dysplasia of the hip (CDH) is to place the child in traction for 2 weeks then perform an arthrogram and closed reduction followed by the application of a hip spica. We wanted to evaluate the incidence of a vascular necrosis (AVN) of the femoral head following closed reduction of the hip. Methods: We have retrospectively reviewed all case notes for patients with congenital dysplastic hips (CDH) that had dislocated hips over a 20 year period from 1993-2013. Data was collected from clinic letters and radiographs. Results: There were 34 children with CDH and dislocated hips. The mean (±S.D) age at closed reduction was 14(±6) months. The mean follow up period was to 6(±3) years. One patient had features of AVN noted on radiographs at age 7 years (2.9%). This patient’s dislocated hip was reduced closed at age 8 months. In our series only 3 patients required open reduction. Of these 2 were followed by femoral derotation osteotomies. All these 3 patients presented with dislocated hips at greater than 15 months of age. Clinically all patients were functioning with no restrictions at last follow up Conclusion: We have treated children with arthrogram and closed reduction of the hip from the age of 4 months to 33 months resulting in one case of AVN in a child treated at 8 months old. This gives an AVN rate of 1 in 34 (2.9%). We would recommend this to be an acceptable method of management with a very low rate of AVN.