1 Department of Radiology, The Hospital for Sick Children, Toronto, ON, Canada.
2 Present address: Department of Radiology, Royal United Hospital Bath, Combe Park, Bath, Somerset, BA1 3NG, UK.
AJR Am J Roentgenol. 2016 Feb;206(2):426-30. doi: 10.2214/AJR.15.14909. Epub 2015 Nov 20.
The purpose of this study is to correlate the MRI finding of quadratus femoris edema in children with established measures of ischiofemoral impingement in adults and to determine their clinical significance.
A case-control retrospective review was performed of MR images of 12 hips of nine children (mean age, 10 years) that showed abnormal signal intensity in the quadratus femoris muscle. The findings were compared with those for 13 hips in 13 control subjects (mean age, 9.8 years). Two musculoskeletal radiologists independently measured the ischiofemoral space, quadratus femoris space, inclination angle, and hamstring tendon area. Quadratus femoris muscle edema, tears, or fatty replacement were assessed visually. Statistical analysis determined inter- and intraobserver variability and statistical differences between the two subject groups.
Subjects with abnormal signal in the quadratus femoris muscle had a statistically significantly narrower ischiofemoral space (mean, 11.5 vs 20.7 mm; p < 0.05) and quadratus femoris space (mean, 7.2 vs 14.3 mm, p < 0.05) compared with control subjects. Inclination angles were statistically significantly larger in affected subjects (145.5° vs 138.7°; p < 0.05). No statistically significant difference was found in hamstring tendon area. Four of 12 patient hips had no symptoms or symptoms unrelated to the abnormality. Inter- and intraobserver variability scores were strong for all continuous variables.
Ischiofemoral impingement is a cause of hip pain in children and should be considered with the combination of quadratus femoris muscle edema and narrowing of ischiofemoral space and quadratus femoris space. Coxa valga may contribute to narrowing of these parameters and predispose to ischiofemoral impingement. The MRI features of ischiofemoral impingement, however, are nonspecific and may be seen in patients with pain localized to that hip or in patients with symptoms unrelated to the abnormality.
本研究旨在将儿童髋关节四方肌水肿的 MRI 发现与成人髋关节坐骨股骨撞击症的既定测量方法相关联，并确定其临床意义。
对 9 名儿童（平均年龄 10 岁）的 12 个髋关节的 MRI 图像进行了病例对照回顾性分析，这些儿童的四方肌显示异常信号强度。将这些发现与 13 名对照组（平均年龄 9.8 岁）的 13 个髋关节进行了比较。两位肌肉骨骼放射科医生独立测量了坐骨股骨间隙、四方肌间隙、倾斜角和绳肌腱面积。评估了四方肌肌肉水肿、撕裂或脂肪替代的情况。统计分析确定了观察者间和观察者内的变异性以及两组之间的统计学差异。
在四方肌出现异常信号的受试者中，坐骨股骨间隙（平均，11.5 对 20.7mm；p<0.05）和四方肌间隙（平均，7.2 对 14.3mm，p<0.05）明显较对照组狭窄。受影响的受试者的倾斜角度明显较大（145.5°对 138.7°；p<0.05）。绳肌腱面积无统计学差异。12 例患者中有 4 例髋关节无任何症状或与异常无关的症状。所有连续变量的观察者间和观察者内变异性评分均较强。
坐骨股骨撞击症是儿童髋关节疼痛的一个原因，应考虑四方肌水肿和坐骨股骨间隙以及四方肌间隙狭窄的组合。髋外翻可能导致这些参数变窄，并易发生坐骨股骨撞击症。然而，坐骨股骨撞击症的 MRI 特征是不特异的，可能出现在疼痛局限于该髋关节的患者中，也可能出现在与异常无关的症状的患者中。
