Borderline acetabular dysplasia refers to mildly sub-normal patterns of acetabular shape and coverage that might predispose children to mechanical dysfunction and instability. Borderline dysplasia generally includes children with a lateral center edge angle (CEA) of 18-24°. Some children with borderline radiographic measurements have normal joint mechanics and function while others benefit from acetabular reorienting surgery. Although radiographic findings of borderline dysplasia might suggest instability, the ultimate diagnosis is based on history and physical exam in addition to imaging. Children with borderline acetabular dysplasia sometimes benefit from other cross-sectional imaging studies such as MR imaging to evaluate for secondary evidence of instability, including damage along the acetabular rim, or labral degeneration and hypertrophy. CT is also helpful for depiction of 3-D acetabular morphology for preoperative assessment and planning. Pediatric radiologists are often the first to identify borderline or mild dysplasia on radiographs. It is imperative that pediatric radiologists serve as effective consultants and offer appropriate recommendations as part of a cohesive multidisciplinary approach to this complex patient population.

中文翻译：

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边缘性发育不良的髋关节：何时以及如何异常？

边缘性髋臼发育不良是指髋臼形状和覆盖物的轻度亚正常模式，可能使儿童易患机械功能障碍和不稳定。边缘不典型增生通常包括侧向中心边缘角（CEA）为18-24°的儿童。一些进行边缘X线照相的儿童关节力学和功能正常，而其他儿童则从髋臼定向手术中受益。尽管边缘不典型增生的影像学表现可能表明不稳定，但最终的诊断是根据病史和体检以及影像学检查。边缘性髋臼发育不良的儿童有时可从其他横断面成像研究（例如MR成像）中受益，以评估不稳定性的次要证据，包括髋臼缘的损伤或阴唇变性和肥大。CT还有助于描绘3-D髋臼形态，以进行术前评估和计划。儿科放射科医生通常是最早在放射线照片上发现边缘性或轻度不典型增生的人。至关重要的是，儿科放射科医生必须作为有效的顾问并提供适当的建议，以作为针对这种复杂患者群体的具有凝聚力的多学科方法的一部分。