摘要目的:提出儿童股骨近端前倾程度的一种新的测量指标，即股骨颈-小转子前倾角（femoral neck-lesser trochanter anteversion，FN-LTA），并探讨应用该指标来评估儿童单侧发育性髋关节脱位（developmental dislocation of the hip，DDH）股骨近端前倾畸形的可行性及其优势。方法:回顾性分析2016年2月至2017年4月收治的90例单侧DDH患儿的影像学资料，其中男13例，女77例；年龄（2.6±2.3）岁（范围0.6~11岁）。分别测量患侧与健侧的股骨颈前倾角（femoral neck anteversion，FNA）和FN-LTA。分析FN-LTA与FNA的相关性，分析性别、年龄、侧别、脱位程度等因素对FN-LTA的影响，分别比较FNA、FN-LTA患侧与健侧的差异，并分析脱位程度对这种差异的影响，比较FNA、FN-LTA的诊断效能及组内组间一致性。结果:无论健侧还是患侧，FN-LTA与FNA均存在正相关性，健侧 r=0.217（ P=0.040），患侧 r=0.298（ P=0.004）。FNA患侧38.86°±11.70°，健侧35.44°±11.16°；FN-LTA患侧72.19°±9.17°，健侧61.17°±10.30°，差异有统计学意义（均 P<0.05）。性别、侧别、脱位程度等因素对FN-LTA不造成明显影响（ P性别=0.060； P侧别=0.550； P脱位程度健侧=0.130； P患侧=0.705），与年龄呈负相关（ r健侧=-0.261， P健侧=0.013； r患侧=-0.287， P患侧=0.006）。FN-LTA的诊断效能更好，AUC FNA=0.570，AUC FN-LTA=0.780，差异有统计学意义（ P<0.05）。组内 ICCFNA=0.956， ICCFN-LTA=0.973；组间 ICCFNA1=0.937， ICCFNA2=0.893， ICCFN-LTA1=0.887， ICCFN-LTA2=0.874。随着脱位程度的增高，FNA、FN-LTA双侧的差异均减小，但这种减小的趋势在FNA有统计学意义（ P=0.030），而FN-LTA无统计学意义（ P=0.180）。 结论:应用FN-LTA评估DDH患儿股骨近端的前倾畸形是一种可靠的方法，且区分度更高，测得的数据更能够指导去旋转截骨。

abstractsObjective:A new measurement index, femoral neck-lesser trochanter anteversion (FN-LTA), is proposed. To explore the feasibility and advantage of applying the FN-LTA to evaluate the proximal femoral deformity of unilateral developmental dislocation of the hip in children, so as to solve the current clinical problems.Methods:The imaging data of 90 patients with unilateral DDH admitted to our department from February 2016 to April 2017 were retrospectively analyzed, There were 13 males and 77 females. The age ranged from 0.6 to 11 years, with an average of 2.6±2.3 years. Femoral neck anteversion (FNA) and FN-LTA were measured at the affected and healthy sides. Analyze the correlation between FN-LTA and FNA, analyze the influence of gender, age, side, dislocation degree and other factors on FN-LTA, compare the difference between the affected side and the healthy side of FNA, FN-LTA, and analyze the influence of dislocation degree on this difference, compare the diagnostic efficacy and intra group consistency of FNA and FN-LTA. The possible advantages of FN-LTA in clinical application were preliminarily analyzed.Results:There was a positive correlation between FN-LTA and FNA in both healthy and affected sides (healthy side r=0.217, P=0.040, affected side r=0.298, P=0.004). FNA and FN-LTA in the affected side of DDH children were both larger than the healthy side, FNA affected side 38.86°±11.70°, healthy side 35.44°±11.16°; FN-LTA affected side 72.19°±9.17°, healthy side 61.17°±10.30°. The difference had statistical significance. FN-LTA was not affected by gender, side, degree of dislocation and other factors (gender P=0.060, side P=0.550, degree of dislocation of healthy side P=0.130, affected side P=0.705), but negatively correlated with age (healthy side r=-0.261, P=0.013, affected side r=-0.287, P=0.006). The diagnostic efficiency of FN-LTA is better, AUC FNA=0.561, AUC FN-LTA=0.736 ( P<0.05). FN-LTA and FNA had excellent intra group and inter group consistency. Inter group ICCFNA=0.956, ICCFN-LTA=0.973; intra group ICCFNA1=0.937, ICCFNA2=0.893, ICCFN-LTA1=0.887, ICCFN-LTA2=0.874. With the increase of dislocation degree, the difference between FNA and FN-LTA decreased. This decreasing trend was statistically significant in FNA ( P=0.030) but not in FN-LTA ( P=0.180). Conclusion:FN-LTA is a reliable method with a higher degree of differentiation for the assessment of anteverted deformity in DDH children' proximal end of femur, the measured data are more capable of guiding the rotation of osteotomy.