BACKGROUND Patients with developmental dysplasia of the hip (DDH) are at risk for residual acetabular dysplasia even after successful closed reduction. The aim of this study was to identify predictors of long-term outcomes in order to guide prognostication and management. METHODS Patients who were treated for DDH at 2 institutions between 1970 and 2010 and had follow-up until skeletal maturity were screened for inclusion. Hips that underwent open reduction were excluded to reduce iatrogenic confounding. Syndromal (including neuromuscular and arthrogrypotic) hip instability with collagenopathies were excluded. Demographic characteristics, Tönnis grade, age at the time of the reduction, surgical treatment, acetabular index, lateral center-edge angle, residual dysplasia graded using the Severin classification, and the presence and type of proximal femoral growth disturbance categorized using the Bucholz and Ogden classification were assessed. In addition, the the acetabular angle was recorded at the latest follow-up before secondary procedures, and the Oxford Hip Score and 5-level EuroQoL (EQ)-5 Dimension score were recorded at the latest follow-up. To account for repeated measures, generalized estimating equations (GEE) logistic regression was utilized for the multivariable analysis. A support vector machine model and a receiver operating characteristic curve analysis were utilized to identify prognostication thresholds. RESULTS One hundred and seven hips (96 female, 11 male) that were followed to skeletal maturity, with a mean follow-up of 20 years (range, 10 to 54 years), were included in the analysis. Eighty-nine hips (83%) demonstrated a good outcome at skeletal maturity, with a Severin grade of I or II. Major growth disturbances of Bucholz and Ogden types II, III, or IV were present in 13 hips (12%). At the latest follow-up after skeletal maturity (before any secondary procedures), the mean acetabular angle was 45° ± 4° and the mean lateral center-edge angle was 26° ± 8°. The mean Oxford Hip Score and EQ visual analog scale values were 47 and 86, respectively. A GEE logistic regression analysis of 1,135 observations revealed that the acetabular index (odds ratio [OR], 1.16 per degree; p < 0.001) and age (OR, 1.20 per year; p = 0.003) were significant predictors of a poor outcome (i.e., Severin grade III, IV, or V). Significant differences in acetabular indices across all age groups were found between hips with a good outcome and those with a poor outcome. Age-specific acetabular index prognostication cutoff values are presented. CONCLUSIONS This long-term follow-up study demonstrated that the age-specific acetabular index remains an important predictor of residual dysplasia at skeletal maturity. The proposed prognostication chart and thresholds herein can help to guide orthopaedic surgeons and parents when contemplating the use of an intervention versus surveillance to optimize long-term outcomes. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

中文翻译：

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预测发育性髋关节发育不良闭合复位后骨骼成熟时的残余发育不良：一项平均随访 20 年的长期研究。


背景 发育性髋关节发育不良 (DDH) 患者即使在成功闭合复位后仍有残留髋臼发育不良的风险。本研究的目的是确定长期结果的预测因素，以指导预测和管理。方法 筛选 1970 年至 2010 年间在 2 个机构接受 DDH 治疗并随访直至骨骼成熟的患者。排除接受切开复位的髋关节以减少医源性混杂。排除了伴有胶原病的髋关节不稳定综合征（包括神经肌肉性和关节绞痛性）。人口统计学特征、Tönnis 分级、复位时的年龄、手术治疗、髋臼指数、横向中心边缘角度、使用 Severin 分类分级的残余发育不良，以及使用 Bucholz 和 Ogden 分类的近端股骨生长障碍的存在和类型进行了分类评估。此外，在二次手术前记录最近一次随访时的髋臼角，并记录最近一次随访时的牛津髋关节评分和5级EuroQoL（EQ）-5维度评分。为了考虑重复测量，利用广义估计方程（GEE）逻辑回归进行多变量分析。利用支持向量机模型和受试者工作特征曲线分析来确定预测阈值。结果 107 个髋关节（96 个女性，11 个男性）被纳入分析，这些髋关节的骨骼成熟期平均为 20 年（范围为 10 至 54 年）。 89 个髋关节 (83%) 在骨骼成熟度方面表现出良好的结果，Severin 等级为 I 或 II。 13 个髋关节（12%）存在 II、III 或 IV 型 Bucholz 和 Ogden 的主要生长障碍。在骨骼成熟后的最后一次随访中（在任何二次手术之前），平均髋臼角为 45° ± 4°，平均横向中心边缘角为 26° ± 8°。平均牛津髋关节评分和 EQ 视觉模拟量表值分别为 47 和 86。对 1,135 个观察结果进行的 GEE 逻辑回归分析显示，髋臼指数（比值比 [OR]，每度 1.16；p < 0.001）和年龄（OR，每年 1.20；p = 0.003）是不良结果的显着预测因素（即，Severin III、IV 或 V 级）。在所有年龄组中，结果良好的髋关节和结果较差的髋关节之间的髋臼指数存在显着差异。给出了年龄特异性髋臼指数的预测截止值。结论 这项长期随访研究表明，年龄特异性髋臼指数仍然是骨骼成熟时残余发育不良的重要预测因子。本文提出的预测图和阈值可以帮助指导整形外科医生和家长在考虑使用干预与监测来优化长期结果时。证据级别 预后 III 级。有关证据级别的完整描述，请参阅作者须知。