Abstract
Background It remains controversial whether the older age at closed reduction (CR) of developmental dysplasia of the hip (DDH), the higher incidence of complications. The aim of this study is to evaluate the Mid-term outcome of CR for DDH among difference age groups, and to analyze and identify risk factors for the failure of this procedure. Methods Clinical data of DDH patients, who received CR, were retrospectively reviewed. Hips were divided into three groups according to initial age (Group I: <12 months; Group II: 12 months to ≤18 months; Group III: >18 months). The presence of avascular necrosis (AVN), residual acetabular dysplasia (RAD), re-dislocation, further surgeries (FS) and failure of CR were observed. The risk factors were identified for those outcomes abovementioned. Receiver operating characteristics (ROC) curve analysis based on age, pre-op AI and post-op AI for failure was conducted.Results A total of 107 patients (156 hips) undergoing CR were evaluated with a median age at initial reduction of 13.0 months (range, 4 to 28 mo). Mean follow-up time in this study was 6.7 years (range, 3-8 years). The incidence of AVN, RAD and re-dislocation was 15.4% (24/156), 17.3% (27/156) and 14.7% (23/156). For AVN, RAD and re-dislocation, the risk factors were pre-op IHDI IV (p=0.033), age≥18 months (p=0.012), and pre-op IHDI IV and walking (p=0.004 and p=0.011), respectively. The areas under the ROC curve of failure were 0.841 (post-op AI), 0.688 (pre-op AI) and 0.650 (age).Conclusions RAD is a complication that must be carefully considered for severe patients older than 18 months before CR. Re-dislocation is associated with pre-op IHDI IV and walking. Patients, who are older than 12.5 months or have a pre-op AI of 38.7° or a post-op AI of 26.4°, are more likely fail of CR.