Amodio John, Rivera Rafael, Pinkney Lynne, Strubel Naomi, Fefferman Nancy
Department of Radiology, New York University Medical Center, 560 First Ave., New York, NY 10016, USA.
Pediatr Radiol. 2006 Aug;36(8):841-4. doi: 10.1007/s00247-006-0171-9. Epub 2006 May 11.
The arterial vascularity of the hip has been investigated in normal infants using duplex Doppler sonography. This study addressed the differences in hip vascularity in infants with respect to gender and acetabular morphology.
To determine whether there is a relationship between the resistive index of the vessels of the femoral chondroepiphysis and the alpha angle in normal infant hips and in those with developmental dysplasia of the hip.
We studied 76 hips (38 patients) with gray-scale and power Doppler US. The patients were referred because of a possible abnormal clinical hip examination or had risk factors for developmental dysplasia of the hip. The infants ranged in age from 1 day to 6 weeks. There were 13 boys and 25 girls. Gray-scale images were initially performed in the coronal and transverse planes to evaluate acetabular morphology, alpha angle and position of the femoral chondroepiphysis relative to the acetabulum. The hips were then examined with power Doppler US, in both sagittal and transverse planes, to identify arterial vessels within the femoral epiphysis. Resistive indices were then recorded from the spectral analysis in each vessel identified. Each examination was performed by one of five pediatric radiologists. Mixed model regression was used to assess the relationship between resistive index and alpha angle, age and gender.
Of the 76 hips, 34 had an alpha angle of 60 degrees or greater and were classified as normal, 26 had an alpha angle between 50 degrees and 59 degrees and were classified as immature, and 13 had an alpha angle of less than 50 degrees and were either subluxed or dislocated at the time of examination. At least two vessels were documented in each femoral epiphysis except in three hips, in which no vessels could be documented because of technical factors. There was a statistically significant linear relationship between the alpha angle and resistive index, such that the resistive index tended to rise with increasing alpha angle (P=0.0022). In addition, female infants had a significantly higher average resistive index than the average resistive index in male infants with the same alpha angle (P=0.0005).
There is a direct linear relationship between alpha angle and resistive index in the infant hip. Female infants have a higher average resistive index than male infants. We believe that these results might serve as a model for predicting an infant hip at risk of ischemia. In addition, the fact that lower resistive indices of the femoral epiphysis are associated with acetabular dysplasia might help explain the documented low incidence of avascular necrosis in untreated hip dysplasia.
已使用双功多普勒超声对正常婴儿的髋部动脉血管情况进行了研究。本研究探讨了婴儿髋部血管情况在性别和髋臼形态方面的差异。
确定在正常婴儿髋部以及患有发育性髋关节发育不良的婴儿髋部中，股骨软骨骨骺血管的阻力指数与α角之间是否存在关联。
我们使用灰阶和能量多普勒超声对76个髋部（38例患者）进行了研究。这些患者因临床髋部检查可能异常或具有髋关节发育不良的危险因素而被转诊。婴儿年龄从1天至6周不等。其中有13名男孩和25名女孩。最初在冠状面和横断面上进行灰阶成像，以评估髋臼形态、α角以及股骨软骨骨骺相对于髋臼的位置。然后在矢状面和横断面上用能量多普勒超声对髋部进行检查，以识别股骨骨骺内的动脉血管。随后从所识别的每个血管的频谱分析中记录阻力指数。每次检查由五名儿科放射科医生之一进行。使用混合模型回归来评估阻力指数与α角、年龄和性别的关系。
在这76个髋部中，34个α角为60度或更大，被归类为正常；26个α角在50度至59度之间，被归类为未成熟；13个α角小于50度，并在检查时出现半脱位或脱位。除了三个髋部因技术因素未记录到血管外，每个股骨骨骺至少记录到两条血管。α角与阻力指数之间存在统计学上显著的线性关系，即阻力指数倾向于随着α角的增加而升高（P = 0.0022）。此外，在相同α角的情况下，女婴的平均阻力指数显著高于男婴的平均阻力指数（P = 0.0005）。
婴儿髋部的α角与阻力指数之间存在直接的线性关系。女婴的平均阻力指数高于男婴。我们认为这些结果可能作为预测有缺血风险的婴儿髋部的一个模型。此外，股骨骨骺较低的阻力指数与髋臼发育不良相关这一事实，可能有助于解释未经治疗的髋关节发育不良中记录的低骨坏死发生率。
