超声与机械装置结合IMU评估儿童胫骨及胫腓骨扭转指数的可靠性
前瞻性研究纳入20名7-9岁健康儿童（40根胫骨），评估超声胫骨扭转指数（TTI）和机械胫腓骨扭转指数（TFTI）的观察者内与观察者间信度。TTI观察者内ICC为0.98、观察者间为0.86；TFTI分别为0.85和0.70；两种方法相关性弱（r=0.35），平均差异14.7°。两者可重复性均良好，超声TTI观察者间信度更优且儿童接受度高。
要点
- 超声TTI观察者间信度良好（ICC=0.86），优于机械TFTI（ICC=0.70）。
- TTI与TFTI相关性弱（r=0.35），不可直接互换，平均差异14.7°。
- 测量误差SEM为1.6°-3.8°，最小可检测变化SDC95为4.4°-10.4°。
核心结论
- 超声TTI和机械TFTI在儿童中均具有可重复性，但超声TTI观察者间信度更优，可能成为儿童友好的无辐射监测胫骨扭转的选择。
研究设计与样本
- 前瞻性信度研究，纳入20名7-9岁健康儿童共40根胫骨，由两名独立观察者分不同日重复测量。
- TTI采用超声结合探头上的紧凑型惯性测量单元（IMU），TFTI采用两个机械装置序贯使用单个IMU。
- 信度指标包括ICC(2,1)及95%CI、测量标准误（SEM）和最小可检测变化（SDC95），并评估儿童接受度。
诊断标准与关键数值
- TTI观察者内ICC(2,1)=0.98，观察者间ICC(2,1)=0.86；TFTI观察者内ICC(2,1)=0.85，观察者间ICC(2,1)=0.70。
- SEM范围为1.6°-3.8°，SDC95范围为4.4°-10.4°。
- TTI与TFTI相关性弱（r=0.35；ρ=0.30），Bland-Altman平均差异14.7°并存在比例偏倚。
- 儿童接受度高：舒适度中位数5、无痛5、愿意重复4/5（Likert量表）。
临床应用与阅片要点
- 超声TTI可作为儿童胫骨扭转的无辐射监测工具，但需注意观察者间信度仍非完美（ICC=0.86）。
- TTI与TFTI相关性弱且平均差异达14.7°，临床解读时不可将两种方法结果直接互换或等同。
- SEM和SDC95提示测量误差范围，判读变化时应考虑最小可检测变化（4.4°-10.4°）以避免过度解读。
- 儿童接受度高，适合重复随访，但需标准化 landmarks 和 IMU 操作以减小观察者间变异。
局限性
- 研究样本量小（20名儿童，40根胫骨），仅纳入7-9岁健康儿童，外推至其他年龄或患者群体需谨慎。
- TTI与TFTI相关性弱，但未与金标准（如CT）比较，两者准确性未知。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
英文原文（摘要）· 点击展开
OBJECTIVE: To assess the intra- and inter-observer reliability of two non-invasive tibial torsion indices in children-the ultrasound-based Tibial Torsion Index (TTI) and the mechanically based Tibiofibular Torsion Index (TFTI)-and to examine their agreement and child acceptability.
MATERIALS AND METHODS: Prospective reliability study in 20 healthy children aged 7-9 years (40 tibiae). TTI was obtained with ultrasound using standardized landmarks and a compact inertial measurement unit (IMU) mounted on the probe; TFTI with two mechanical devices using a single IMU sequentially. Two independent observers performed assessments (Observer 1 on Day 1 and Day 2; Observer 2 on Day 2). Reliability metrics included intraclass correlation coefficients (ICC(2,1), 95% CI), standard error of measurement (SEM) and smallest detectable change (SDC95). Intrasession variability was expressed as within-session SD. Agreement was evaluated using correlation, Bland-Altman plots and regression analyses. Child acceptability regarding pain, comfort and willingness to repeat was recorded on a Likert-type scale supported by a faces-based visual aid.
RESULTS: TTI showed excellent intra-observer (ICC(2,1) = 0.98) and good inter-observer reliability (ICC(2,1) = 0.86). TFTI showed good intra-observer (ICC(2,1) = 0.85) and moderate inter-observer reliability (ICC(2,1) = 0.70). SEM ranged 1.6°-3.8°; SDC95 4.4°-10.4°. Correlation between TTI and TFTI was weak (r = 0.35; ρ = 0.30); Bland-Altman indicated a mean difference of 14.7° with proportional bias. Acceptability was high (median comfort 5, pain-free 5, willingness-to-repeat 4/5).
CONCLUSION: Both indices were reproducible. The ultrasound-based TTI demonstrated superior inter-observer reliability and may represent a child-friendly, radiation-free option for monitoring tibial torsion in pediatric practice.
引用
- Ruiz-Tarrazo X, Coda A, Sánchez-Dueñas C, et al. Reliability of Tibial and Tibiofibular Torsion Indices Using Ultrasound and Mechanical Devices With an Inertial Measurement Unit (IMU) in Children. Ultrasound Med Biol. 2026. PMID: 42002445. doi:10.1016/j.ultrasmedbio.2026.03.012
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。