Department of Radiology, Auckland City Hospital, Auckland, New Zealand.
School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.
Skeletal Radiol. 2023 Jun;52(6):1127-1135. doi: 10.1007/s00256-022-04248-6. Epub 2022 Dec 7.
To evaluate the prevalence of the 'posterior crescent sign' in symptomatic patients referred for MRI/MR arthrogram of the hip and identify any correlation with imaging features of joint pathology.
Retrospective imaging assessment of a cohort of 1462 hips, from 1380 included MR examinations (82 bilateral) retrieved from a search of all examinations in patients 16-50 years old from June 2018 to June 2021, with median age 45.8 years (range 17.8-50.0) and 936 hips (64%) in women. Radiographic and MR findings related to hip dysplasia, femoroacetabular impingement and osteoarthritis were assessed.
Fifty-one hips (3.5%) were positive for the posterior crescent sign, median age of 45.8 years (range 17.8-50.0) and 29 (58%) in women. Radiographic findings included the following: mean lateral centre edge angle (LCEA) 22.2° (± 7.8°) with LCEA < 20° in 15 (31%) and LCEA 20-25° in 17 (35%) and mean acetabular index (AI) of 13.1° (± 5.8°) with AI > 13° in 22 (45%). MR findings included the following: mean anterior acetabular sector angle (AASA) 54.3° (± 9.8°), mean posterior acetabular sector angle (PASA) 92.7° (± 7.0°), labral tear at 3-4 o'clock in 20 (39%), high-grade acetabular chondral loss in 42 (83%) and ligamentum teres abnormality in 20 (39%).
The posterior crescent sign occurs in 3.5% of symptomatic young and middle-aged adults on MR. It is associated with overt and borderline hip dysplasia and other findings of hip instability. It is also associated with osteoarthritis in some cases and should be interpreted with caution in these patients.
评估有症状患者进行髋关节 MRI/MR 关节造影术时出现“后新月征”的发生率，并确定其与关节病变影像学特征的任何相关性。
回顾性分析了 1380 例接受检查的患者中 1462 例髋关节的影像学资料（82 例为双侧髋关节），这些患者均于 2018 年 6 月至 2021 年 6 月间接受了年龄在 16-50 岁（中位数 45.8 岁，范围 17.8-50.0 岁）的患者的所有检查，其中 936 例（64%）为女性。评估了髋关节发育不良、股骨髋臼撞击症和骨关节炎的放射学和 MR 表现。
51 例（3.5%）髋关节的后新月征阳性，中位数年龄为 45.8 岁（范围 17.8-50.0 岁），其中 29 例（58%）为女性。放射学发现包括：平均外侧中心边缘角（LCEA）为 22.2°（±7.8°），其中 15 例（31%）LCEA<20°，17 例（35%）LCEA 20-25°，髋臼指数（AI）平均值为 13.1°（±5.8°），其中 22 例（45%）AI>13°。MR 发现包括：平均前髋臼扇形角（AASA）为 54.3°（±9.8°），平均后髋臼扇形角（PASA）为 92.7°（±7.0°），3-4 点处的髋臼唇撕裂 20 例（39%），高等级髋臼软骨丢失 42 例（83%），圆韧带异常 20 例（39%）。
在有症状的年轻和中年成年人的 MRI 中，后新月征的发生率为 3.5%。它与明显和临界髋关节发育不良以及其他髋关节不稳定的发现有关。在某些情况下，它也与骨关节炎有关，因此在这些患者中应谨慎解释。
