儿童发育性髋关节发育不良闭合复位术后结局预测模型的构建OA北大核心CSTPCD

Objective To establish a prediction model for residual acetabular dysplasia(RAD)follow-ing closed reduction in developmental dysplasia of the hip(DDH),so as to guide the selection of timing for secondary pelvic osteotomy.Methods A retrospective analysis was performed on 449 patients(522 hips,mean age:16.3±5.1 months)with DDH treated by closed reduction from 2004 to 2015.On pelvic radiograph,the de-gree of dislocation according to International Hip Dysplasia Institute(IHDI)classification and the appearance of ossified nuclei were evaluated prior to reduction,and acetabular index(AI),Centre-edge angle of Wiberg(CEA)and Reimer index(RI)were measured at the time of 1,2,3,4 years postoperation.and final follow up visit.Avas-cular necrosis of the femoral head(AVN)was also assessed.Patients were divided into two groups according to Severin's grade at last follow-up and whether they underwent secondary pelvic osteotomy:those with Severin Ⅰ/Ⅱhips were classied into the recovered group and those with Severin Ⅲ/Ⅳ hips or already having undergone pelvic osteotomy were classified into the RAD group.Cox regression was used to establish a predictive model for recovery of the hip after closed reduction,and the receiver operating characteristic curve(ROC)analysis was used to veri-fy the established model.Results Of these 522 hips,70 hips(13.4％)were IHDI type Ⅱ,223(44.6％)were type Ⅲ and 219(42％)were type Ⅳ.Prior to reduction,the ossified nuclei of the femoral head appeared in 410 hips(78.5％).The overall incidence of AVN was 12.8％.There were 329 hips(63％)involved in recovered group.Of these 329 hips,the mean recovery time was 33.3±14.7 months,and 93.6％of these patients recovered within 5 years after surgery.Cox regression analysis showed that IHDI classification,ossification nucleus of the femoral head,age of reduction,and current AI,CEA,RI and AVN were factors affecting the cumulative probability of recovery after closed reduction of DDH.Based on Cox regression analysis,this study successfully constructed a predictive model for recovery after closed reduction.The total scores of this model ranged from-11 to 17,with corresponding cumulative probability of recovery ranged from 0.02 to 1.0.Under this model,if the total score was less than or equal to 2.5,1.5,2.5,or 1.5 points at 1,2,3,and 4 years after CR,respectively,the patient had a significantly higher rate of recovery(81.4％-96.1％),the area under the curve of ROC was 0.808 to 0.910,and the Kappa coefficient was 0.497 to 0.618.On the other hand,if the total score was larger than 1.5-2.5,the risk of RAD significantly increased,and pelvic osteotomy was recommended under this condition.Conclusions The model established in this study can be effectively used to predict the development of RAD,so as to guide the timing of pelvic osteotomy.Under this model,the child is very likely to develop RAD if the total score is greater than 2.5,1.5,2.5,or 1.5 points at 1,2,3,and 4 years after CR,respectively.