Purpose

To determine the accuracy of US for the quantitative parameters of cam-type femoroacetabular impingement (FAI) in an asymptomatic adult population, using MRI as the reference standard.

Materials and methods

We prospectively evaluated 158 hips of 79 adult subjects (44 males, 35 females; age range 18–49 years) with a negative anterior impingement test. Two observers independently measured anterosuperior quadrant alpha angles and anterior femoral distances (AFDs) on both US and MRI.

Results

US measurements of alpha angle and AFD had a moderate-to-high positive correlation with MRI measurements and there was substantial and/or almost perfect agreement between observers on both imaging modalities. Anterior femoral distance measurements for both observers and alpha angles at MRI for Observer 1 showed no statistically significant difference between genders.

Conclusion

Ultrasonography can be used for anterosuperior alpha angle and AFD measurements in asymptomatic adults. However, when used as the sole imaging method, its inherent limitations and possible discrepancies with MRI should be kept in mind.

中文翻译：

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美国对凸轮型股骨髋臼撞击参数测量的有效性：在无症状成人人群中的初步研究。

目的

为了确定无症状成人人群中凸轮型股骨髋臼撞击（FAI）定量参数的美国准确性，使用MRI作为参考标准。

材料和方法

我们前瞻性评估了79名成年受试者的158髋（男性44例，女性35例；年龄18-49岁）。两名观察者分别在US和MRI上测量了上上象限的α角和股骨前距离（AFD）。

结果

美国对α角和AFD的测量与MRI测量具有中等到较高的正相关，并且观察者之间在两种成像方式上都达成了实质性和/或几乎完美的共识。观察者的前部股骨距离测量值以及观察者1的MRI的α角测量结果表明，性别之间无统计学差异。

结论

超声检查可用于无症状成年人的前上角和AFD测量。但是，当用作唯一的成像方法时，应牢记其固有的局限性以及与MRI可能存在的差异。