摘要目的:观察发育性髋关节发育不良(developmental dysplasia of the hip，DDH)闭合复位后内翻盂唇的转归及其对髋臼发育的影响。方法:收集2014年3月至2015年6月在中国医科大学附属盛京医院行闭合复位治疗的26例(29髋)DDH患儿的临床资料。其中，男3例，女23例；复位时患儿的平均年龄为13个月，年龄范围为4～28个月；平均随访时间为50个月，随访时间范围为39～61个月。本研究患儿的纳入标准为在闭合复位后的磁共振成像(magnetic resonance imaging，MRI)检查图像显示存在盂唇内翻。将所有患儿按照在最后随访时是否存在内翻盂唇分为残余内翻组(19例，22髋)及内翻消失组(7例，7髋)。比较两组在复位前的IHDI分型、骨性及软骨性髋臼指数和复位后盂唇内翻程度方面的差异，及在最后随访时的骨性及软骨性髋臼指数、盂唇内翻程度、中心边缘角及股骨头骨骺核高宽指数方面的差异，并比较发生股骨头缺血性坏死(avascular necrosis of femoral head，AVN)的情况。结果:复位前残余内翻组IHDI分型为Ⅲ型、Ⅳ型各11髋；内翻消失组Ⅱ型3髋，Ⅲ型4髋( P<0.001)。残余内翻组与内翻消失组术前的骨性髋臼指数之间的差异( P＝0.261)及软骨性髋臼指数之间的差异( P＝0.843)均无统计学意义；复位后当时残余内翻组与内翻消失组的盂唇内翻程度分别为(55.10±9.60)%与(43.92±17.59)%，差异具有统计学意义( P＝0.005)。最后随访时的骨性髋臼指数，残余内翻组为(24.73±5.72)°，内翻消失组为(19.57±2.23)°，差异具有统计学意义( P＝0.029)；最后随访时的软骨性髋臼指数，残余内翻组为(16.68±4.05)°，内翻消失组为(14.71±2.36)°，差异无统计学意义( P＝0.236)；最后随访时的中心边缘角，残余内翻组为(20.77±8.82)°，内翻消失组为(18.86±6.89)°，差异无统计学意义( P＝0.605)；最后随访时的股骨头骨骺核高宽指数，残余内翻组为(44.13±4.24)，内翻消失组为(48.11±6.84)，差异无统计学意义( P＝0.074)。残余内翻组在复位后与最后随访时的盂唇内翻程度相比，差异无统计学意义( P＝0.183)。残余内翻组有5髋[22.73%(5/22)]发生AVN，均为Kalamchi-MacEwen Ⅰ型，内翻消失组无AVN发生。 结论:DDH闭合复位后，大部分内翻盂唇短期内不能吸收，而是演变为一薄层纤维组织嵌插于头臼之间，这可导致髋臼软骨的骨化延迟，但对髋臼发育的远期影响仍需进一步观察。

abstractsObjective:To observe the fate of an interpositional limbus after closed reduction in children with developmental dysplasia of the hip (DDH) and its effect on acetabular development.Methods:The follow-up data were reviewed for 26 DDH patients (29 hips) undergoing closed reduction were collected during March 2014 to June 2015. There were 3 boys and 23 girls with an average age of 13(4-28) months. The average follow-up period was 50(39-61) months. The inclusion criteria was visualization of inverted limbus on magnetic resonance imaging (MRI) after closed reduction. According to the presence or absence of inverted limbus at the final follow-up, they were further divided into residual inversion group (n=19, 22 hips) and inversion disappearing group (n=7, 7 hips). The International Hip Dysplasia Institute (IHDI) classification, osseous and cartilage acetabular index (OAI/CAI) pre-reduction; degree of limbus inversion post-reduction; OAI, CAI, centre-edge angle (CEA), height-to-width index (HWI) of capital epiphysis and avascular necrosis (AVN) at the last follow-up were analyzed.Results:There were 11 hips of IHDI type Ⅲ and type Ⅳ respectively in residual inversion group; 3 hips of typeⅡand 4 hips of type Ⅲ in inversion disappeared group pre-reduction ( P<0.001). No statistical significance existed in OAI/CAI between residual inversion and inversion disappearing groups ( P=0.261, 0.843). The degree of limbus inversion post-reduction was (55.10±9.60)% and (43.92±17.59)% in residual inversion and inversion disappearing groups respectively ( P=0.005). At the last follow-up, AI was (24.73±5.72)°and (19.57±2.23)°in residual inversion and inversion disappearing groups respectively ( P=0.029). At the last follow-up, CAI was (16.68±4.05)°and (14.71±2.36)°in residual inversion and inversion disappearing groups ( P=0.236). At the last follow-up, CEA was (20.77±8.82)°and (18.86±6.89)° in residual inversion and inversion disappearing groups ( P=0.605); HWI (44.13±4.24) and (48.11±6.84) in residual inversion and inversion disappearing groups ( P=0.074). The degree of limbus inversion between after reduction had no significant difference ( P=0.183) and at last follow-up in residual inversion group. Five hips (22.73%) were identified as Kalamchi-MacEwen type Ⅰ AVN in residual inversion group. Conclusions:After closed reduction of DDH, most cases of interpositional limbus can not be absorbed within a short time. And compression into a thin layer of fiber tissue interpositioning between acetabulum and femoral head delays the ossification of acetabular cartilage. Its long-term effects on acetabular development require further observations.