Khalil A, Morales-Roselló J, Morlando M, Bhide A, Papageorghiou A, Thilaganathan B
Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's University of London, London, UK.
Ultrasound Obstet Gynecol. 2014 Jul;44(1):69-75. doi: 10.1002/uog.13339.
It has recently been reported that fetuses with achondroplasia have a wider than expected femoral proximal diaphysis-metaphysis angle (femoral angle). The aim of this case-control study was to investigate this finding.
Cases with confirmed achondroplasia (n = 6), small-for-gestational-age fetuses (n = 70) and a group of normal fetuses (n = 377) were included in this study. The ultrasound image of the femur was examined by two independent experienced observers blinded to the diagnosis, who measured the femoral angle. These values were converted into multiples of the expected median (MoM), after adjustment for gestational age and femur length. Prevalence of various prenatal ultrasound signs of achondroplasia was determined in affected fetuses. Intra- and interobserver agreement of measurement of femoral angle was assessed using 95% limits of agreement and kappa statistics.
The femoral angle can be measured accurately by ultrasound, and increases with both increasing gestational age and increasing femur length. The femoral angle-MoM was significantly higher in fetuses with achondroplasia than in the control group (1.36 vs 1.00 MoM, P < 0.001) and in the SGA group (1.36 vs 1.04 MoM, P < 0.001). It measured more than 130° in five of the six cases with achondroplasia (83.3%), which was the most consistent finding other than shortening of the long bones.
The femoral angle is wider in fetuses with achondroplasia. This new ultrasound sign appears promising as an additional discriminatory marker when clinicians are faced with a case of short long bones in the third trimester.
最近有报道称，患软骨发育不全的胎儿股骨近端骨干-干骺端角（股骨角）比预期更宽。本病例对照研究旨在调查这一发现。
本研究纳入确诊为软骨发育不全的病例（n = 6）、小于胎龄儿（n = 70）和一组正常胎儿（n = 377）。由两名对诊断不知情的独立经验丰富的观察者检查股骨的超声图像，他们测量股骨角。在对孕周和股骨长度进行调整后，将这些值转换为预期中位数的倍数（MoM）。确定受影响胎儿中软骨发育不全各种产前超声征象的患病率。使用95%一致性界限和kappa统计量评估观察者内和观察者间股骨角测量的一致性。
股骨角可通过超声准确测量，且随孕周增加和股骨长度增加而增大。患软骨发育不全的胎儿股骨角-MoM显著高于对照组（1.36 vs 1.00 MoM，P < 0.001）和小于胎龄儿组（1.36 vs 1.04 MoM，P < 0.001）。在6例软骨发育不全病例中的5例（83.3%）中，该角度测量值超过130°，这是除长骨缩短外最一致的发现。
患软骨发育不全的胎儿股骨角更宽。当临床医生在孕晚期遇到长骨短小的病例时，这一新的超声征象作为一种额外的鉴别标志物似乎很有前景。
