Clinical and radiological outcomes are correlated with the age of the child in single-stage surgical treatment of developmental dysplasia of the hip.

The principles of treatment of developmental dislocation of the hip (DDH) in an older child are different from those in a newborn. In the older child retraction of the muscles around the hip, associated with a marked acetabular dysplasia and elongation of the joint capsule explain the difficulty and instability of reduction and the frequency of complications. The aim of this study is to evaluate the effect of age on the results of a one-stage open reduction in developmental dislocation of the hip. We present the results of 21 children (27 hips) with a mean age of 6 years and 10 months at time of operation, consisting of one- stage open reduction, femoral shortening and Salter or triple pelvic osteotomy. Two groups were formed : one older and one younger than 8 years of age. We evaluated the patients according to the Severin and Mc Kay classifications. After an average follow-up of 49 months (24-84 months) 74% of patients showed a very good or good result according to Severin's radiological classification and 63% according to Mc Kay's clinical classification. When analyzed with regard to age, we found important differences in the clinical and radiological results between the children younger and older than 8 years.