Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 North Caroline Street, Baltimore, MD 21287, United States; Department of Orthopaedic Surgery, Medstar Union Memorial Hospital, 201 E University Pkwy, Baltimore, MD 21218, United States; Department of Foot and Ankle Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, United States.
Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 601 North Caroline Street, Baltimore, MD 21287, United States.
Foot Ankle Surg. 2019 Dec;25(6):790-797. doi: 10.1016/j.fas.2018.10.008. Epub 2018 Nov 5.
Clinical assessment of hindfoot alignment (HA) in adult acquired flatfoot deformity (AAFD) can be challenging and weightbearing (WB) cone beam CT (CBCT) may potentially better demonstrate this three-dimensional (3D) deformity. Therefore, we compared clinical and WB CBCT assessment of HA in patients with AAFD.
In this prospective study, we included 12 men and 8 women (mean age: 52.2, range: 20-88) with flexible AAFD. All subjects also underwent WB CBCT and clinical assessment of hindfoot alignment. Three fellowship-trained foot and ankle surgeons performed six hindfoot alignment measurements on the CT images. Intra- and Inter-observer reliabilities were calculated using intra-class correlation (ICC). Measurements were compared by paired T-tests, and p-values of less than 0.05 were considered significant.
The mean of clinically measured hindfoot valgus was 15.2 (95% confidence interval [CI]: 11.5-18.8) degrees. It was significantly different from the mean values of all WB CBCT measurements: Clinical Hindfoot Alignment Angle, 9.9 (CI: 8.9-11.1) degrees; Achilles tendon/Calcaneal Tuberosity Angle, 3.2 (CI: 1.3-5.0) degrees; Tibial axis/Calcaneal Tuberosity Angle, 6.1 (CI: 4.3-7.8) degrees; Tibial axis/Subtalar Joint Angle 7.0 (CI: 5.3-8.8) degrees, and Hindfoot Alignment Angle 22.8 (CI: 20.4-25.3) degrees. We found overall substantial to almost perfect intra- (ICC range: 0.87-0.97) and inter-observer agreements (ICC range: 0.51-0.88) for all WB CBCT measurements.
Using 3D WB CBCT can help characterize the valgus hindfoot alignment in patients with AAFD. We found the different CT measurements to be reliable and repeatable, and to significantly differ from the clinical evaluation of hindfoot valgus alignment.
Level II-prospective comparative study.
成人获得性平足症（AAFD）的后足对线临床评估可能具有挑战性，负重（WB）锥形束 CT（CBCT）可能更好地显示这种三维（3D）畸形。因此，我们比较了 AAFD 患者的临床和 WB CBCT 后足对线评估。
在这项前瞻性研究中，我们纳入了 12 名男性和 8 名女性（平均年龄：52.2 岁，范围：20-88 岁），均患有柔韧性 AAFD。所有患者均接受 WB CBCT 和后足对线的临床评估。三位足踝 fellowship培训的医生在 CT 图像上进行了六次后足对线测量。采用组内相关系数（ICC）计算内部和观察者间可靠性。采用配对 t 检验比较测量值，p 值小于 0.05 认为差异有统计学意义。
临床测量的后足外翻平均值为 15.2°（95%置信区间 [CI]：11.5-18.8）。与所有 WB CBCT 测量值的平均值有显著差异：临床后足对线角为 9.9°（CI：8.9-11.1）；跟腱/跟骨结节角为 3.2°（CI：1.3-5.0）；胫骨轴/跟骨结节角为 6.1°（CI：4.3-7.8）；胫骨轴/距下关节角为 7.0°（CI：5.3-8.8），后足对线角为 22.8°（CI：20.4-25.3）。我们发现，所有 WB CBCT 测量值的内部观察者（ICC 范围：0.87-0.97）和观察者间（ICC 范围：0.51-0.88）一致性均为高度可靠到几乎完全可靠。
使用 3D WB CBCT 可以帮助描述 AAFD 患者的后足外翻对线。我们发现不同的 CT 测量值可靠且可重复，并且与后足外翻对线的临床评估有显著差异。
II 级-前瞻性比较研究。
