儿童发育性髋关节脱位闭合复位失败的风险因素分析

The risk factors of failure of reduction in children with developmental dysplasia of the hip treated by closed reduction and cast immobilization

目的探讨儿童发育性髋关节脱位(developmental dysplasia of the hip,DDH)闭合复位失败的风险因素。方法收集2015年7月至2018年11月收治的采用闭合复位石膏固定治疗的DDH共160例173髋,年龄(15.3±4.4)个月。记录患儿的性别、左右侧、单双侧、手术时年龄、术前是否pavlic治疗、股骨头骨骺是否出现、国际髋关节发育不良研究所(international hip dysplasia institute classification,IHDI)分级、术前髋臼指数(acetabular index,AI)、安全角范围、术中造影盂唇内翻、髋关节内侧池间隙(medial pool distance of hip,MPD)、髋关节外展角度等临床及影像学资料。采用Logistic回归分析、卡方检验及Fisher确切概率法分析DDH合复位失败的风险因素。结果173髋中16髋(9.2%)闭合复位失败,7髋(43.8%)调整复位及石膏后重新获得稳定复位,修正后闭合复位失败率为5.2%(9/173)。单因素Logistic回归分析提示性别、年龄、术前AI和盂唇内翻、髋关节内侧池间隙是DDH闭合复位失败的可能风险因素。多因素Logistic回归分析提示术前AI与髋关节内侧池间隙是DDH闭合复位失败的风险因素。受试者工作特征曲线(ROC曲线)分析提示,髋关节内侧池间隙大于6 mm会显著增加闭合复位失败的风险。盂唇和髋关节内侧池显影不清晰患儿的闭合复位失败率分别为83.3%(5/6)和36.8%(7/19),显著高于盂唇和髋关节内侧池显影清晰患儿6.5%(11/167)和5.8%(9/154),且差异有统计学意义(P<0.001)。根据闭合复位是否成功,将患儿分为闭合复位成功组(157例)和闭合复位失败组(16例),两组术前AI分别为36.8°±4.5°和34.4°±3.7°,组间比较,差异有统计学意义(P<0.05)。结论术前AI和髋关节内侧池间隙是DDH闭合复位失败的风险因素。髋关节内侧池间隙大于6 mm会显著增加DDH患儿闭合复位失败的风险。如术中造影发现盂唇和髋关节内侧池显影不清晰,则闭合复位失败的概率显著增加。

Objective To explore the risk factors of failed reduction after closed reduction in children with developmental dysplasia of the hip(DDH).Methods Retrospective reviews were conducted for the clinical and radiographic data of DDH children undergoing closed reduction and cast immobilization from July 2015 to November 2018.The relevant clinical data were collected,including age,gender,sideness,pavlic treatment pre-reduction,appearance of epiphyseal ossification center,International Hip Dysplasia Institute(IHDI)grade,acetabular index(AI),safe zoom,inverted limbus,medial pool distance of hip(MPD)and abduction angle of hip.The risk factors of failed reduction were evaluated by Logistic regression,t test and Chi-square test and fisher exact probability.Results Sixteen hips(9.2%)failed to achieve initial stable reduction and yet 7 hips(43.8%)obtained stable reduction through a second closed reduction and modified cast immobilization.Thus the modified rate of failed closed reduction was 5.2%(9/173).Single factor Logistic regression indicated that the failure of closed reduction was associated with gender,age,AI,inverted limbus and MPD.Multiple factor Logistic regression showed that MPD and AI are the risk factors.Receiver operating characteristic curve(ROC)showed MPD>6 mm were the risk factors of failure of closed reduction for DDH.The failure rate of closed reduction in children with indistinct limbus(83.3%,5/6)and medial pool(36.8%,7/19)on arthrography were significantly higher than those with distinct limbus(6.5%,11/167)and medial pool(5.8%,9/154)on arthrography(P<0.001).According to the outcome of closed reduction,they were divided into two groups of successful closed reduction(n=157)and failed closed reduction(n=16).The difference of AI of both groups(36.8°±4.5 and 34.4°±3.7°respectively)are statistically significant(P<0.05).Conclusions AI and MPD are the risk factors of failure closed reduction.Patients with MPD>6 mm during operation significantly increase the risk of failure of closed reduction for DDH.Unclearness of limbus and medial pool of hip during arthrography hint the failure of closed reduction for DDH.