Acetabular index and the result of closed reduction in developmental dysplasia of the hip

Objective To establish the relationship between acetabular index and prognosis of closed reduction of DDH in toddlers. Methods Patients were recruited according to the following conditions: age between 1 to 2 years at the beginning of the treatment; in cast for 9 months after reduction, , more than 2 years of follow-up. There were 97 hips in 72 patients. They were categorized into to groups older and younger than 1.5 years of age (A and B).They were further divided into sub-groups according to acetabular index. Severin classification was adopted.χ~2 test was performed to analyze the results. Results The rate of excellence in A1 was 56%.In this group there were 4 avascular necrosis (AVN) cases and 6 patients underwent operations. The rate of excellence in A2 was 24%, 8 hips developed AVN and 10 hips were operated oa The rate of excellence in B1 was 62% and 5 hips were found to have AVN and 3 hips were operated on. The rate of excellence in B2 was only 18%.There were 2 AVN and 10 patients underwent operations. There was significant difference between the subgroups. The rate of excellence in group B2 was low. Conclusions Because of the poor results of closed reduction, we suggest avoiding closed reduction when AI exceed 40 in the toddlers. Key words: Hip dislocation, congenital;  Acetabulum