Department of Orthopaedic Surgery, Murtenstrasse, Inselspital, University of Bern, 3010 Bern, Switzerland.
Clin Orthop Relat Res. 2012 Dec;470(12):3297-305. doi: 10.1007/s11999-012-2473-6.
Developmental dysplasia of the hip (DDH) and acetabular retroversion represent distinct acetabular pathomorphologies. Both are associated with alterations in pelvic morphology. In cases where direct radiographic assessment of the acetabulum is difficult or impossible or in mixed cases of DDH and retroversion, additional indirect pelvimetric parameters would help identify the major underlying structural abnormality.
QUESTIONS/PURPOSES: We asked: How does DDH and retroversion differ with respect to rotation and coronal obliquity as measured by the pelvic width index, anterior inferior iliac spine (AIIS) sign, ilioischial angle, and obturator index? And what is the predictive value of each variable in detecting acetabular retroversion?
We reviewed AP pelvis radiographs for 51 dysplastic and 51 retroverted hips. Dysplasia was diagnosed based on a lateral center-edge angle of less than 20° and an acetabular index of greater than 14°. Retroversion was diagnosed based on a lateral center-edge angle of greater than 25° and concomitant presence of the crossover/ischial spine/posterior wall signs. We calculated sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve for each variable used to diagnose acetabular retroversion.
We found a lower pelvic width index, higher prevalence of the AIIS sign, higher ilioischial angle, and lower obturator index in acetabular retroversion. The entire innominate bone is internally rotated in DDH and externally rotated in retroversion. The areas under the ROC curve were 0.969 (pelvic width index), 0.776 (AIIS sign), 0.971 (ilioischial angle), and 0.925 (obturator index).
Pelvic morphology is associated with acetabular pathomorphology. Our measurements, except the AIIS sign, are indirect indicators of acetabular retroversion. The data suggest they can be used when the acetabular rim is not clearly visible and retroversion is not obvious.
Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.
发育性髋关节发育不良（DDH）和髋臼后倾代表了不同的髋臼病理形态。两者均与骨盆形态改变有关。在直接评估髋臼有困难或不可能的情况下，或者在 DDH 和后倾混合的情况下，额外的间接骨盆参数将有助于确定主要的潜在结构异常。
问题/目的：我们想知道：通过骨盆宽度指数、前下髂棘（AIIS）征、髂坐骨角和闭孔指数测量，DDH 和后倾在旋转和冠状倾斜方面有何不同？以及每个变量在检测髋臼后倾方面的预测价值如何？
我们回顾了 51 例发育不良和 51 例后倾髋关节的 AP 骨盆平片。DDH 基于侧位中心边缘角小于 20°和髋臼指数大于 14°诊断。后倾基于侧位中心边缘角大于 25°和同时存在交叉/坐骨棘/后壁征诊断。我们计算了用于诊断髋臼后倾的每个变量的敏感性、特异性和受试者工作特征（ROC）曲线下面积。
我们发现髋臼后倾的骨盆宽度指数较低、AIIS 征的发生率较高、髂坐骨角较高、闭孔指数较低。整个髋骨在 DDH 中是内旋的，在后倾中是外旋的。ROC 曲线下面积分别为 0.969（骨盆宽度指数）、0.776（AIIS 征）、0.971（髂坐骨角）和 0.925（闭孔指数）。
骨盆形态与髋臼病理形态有关。除了 AIIS 征外，我们的测量结果都是髋臼后倾的间接指标。数据表明，在髋臼边缘不清楚且后倾不明显时，可以使用这些指标。
III 级，诊断研究。有关证据水平的完整描述，请参见作者指南。
