Feasibility Study Of Closed Reduction In Young Children Older Than 18 Months With Developmental Dislocation Of The Hip

Background:Developmental dislocation of the hip(DDH) is one of the most common lower limb abnormalities among young children,earlier diagnose and treatment,especially conservative one,can bring into almost satisfactory morphous development and near-normal function of the hip joint in the future. To date,wide identification on the treatment has been accepted universally, which is conservative treatment(or closed reduction) under the age 18 months and surgery(or open reduction) above the age 36 months.However,great conflicts lie in the treatment between the age 18 months and 36 months.Objective:A retrospective review of hip joint development after closed reduction in young children below and above 18 months old with DDH by ways of radiological parameters has been done to observe whether the development between these two groups is alike or not,accordingly,The purpose is to see whether it is feasible to apply closed reduction to young children above 18 months old with DDH or not.Methods:Seventy eight patients(97 hips),with 70 girls(86 hips) and 8 boys (11 hips),59 unilateral hips and 38 bilateral hips.were observed after closed reduction by X-ray parameters.All patients received combined adductor tenotomy,closed reduction,modified frog-position(or frog-position) plaster fixation and abduction device fixation in Children's Hospital of Fudan University during January,2003 and December,2007,when they were less than 36 months old.The patients were classified into two groups according to the age at reduction,below and above 18 months respectively.X-ray parameters of hip were measured through anteroposterior pelvis rediograph in 6 months,12 months,24 months and 36 months after closed reduction,including acetabular index(Al),medial joint space(MJS),ossific nucleus(ON) of femoral head, center-head distance discrepancy(CHDD),shenton's line,together with avascular necrosis(AVN) and residual acetabular dysplasia(RAD).The average duration of follow-up was 25.2 months(6months to 60 months).Results:There is no statistical differences of changes on radiological parameters of AI.MJS.CHDD and ON after closed reduction between these two groups(p＞0.05,a=0.05),and the shenton's line becomes unstable,from breaking before reduction,intact 6 months after reduction to breaking again when children begin to walk,while the rate of AVN is slightly lower in the group above 18 months(p=0.04,a=0.05) and RAD is higher than that of the group below 18 months(p=0.01,a=0.05).Conclusion:Closed reduction is still available in DDH above the age 18 months with lower rate of AVN while higher of RD.