de Cesar Netto Cesar, Kunas Grace C, Soukup Dylan, Marinescu Anca, Ellis Scott J
1 Hospital for Special Surgery, New York, NY, USA.
Foot Ankle Int. 2018 Jul;39(7):771-779. doi: 10.1177/1071100718762113. Epub 2018 Mar 28.
Previous work has demonstrated that the amount of radiographic hindfoot correction required at the time of adult-acquired flatfoot deformity (AAFD) operative treatment can be predicted by the amount of radiographic deformity present before surgery. Successful outcomes after reconstruction are closely correlated with hindfoot valgus correction. However, it is not clear if differences exist between clinical and radiographic assessment of hindfoot valgus. The purpose of this study was to evaluate the correlation between radiographic and clinical evaluation of hindfoot alignment in patients with stage II AAFD.
Twenty-nine patients (30 feet) with stage II AAFD, 17 men and 12 women, mean age of 51 (range, 20-71) years, were prospectively recruited. In a controlled and standardized fashion, bilateral weightbearing radiographic hindfoot alignment views were taken. Radiographic parameters were measured by 2 blinded and independent readers: hindfoot alignment angle (HAA) and hindfoot moment arm (HMA). Clinical photographs of hindfoot alignment were taken in 3 different vertical camera angulations (0, 20, and 40 degrees). Pictures were assessed by the same readers for standing tibiocalcaneal angle (STCA) and resting calcaneal stance position (RCSP). Intra- and interobserver reliability were assessed by Pearson/Spearman's and intraclass correlation coefficient (ICC), respectively. Relationship between clinical and radiographic hindfoot alignment was evaluated by a linear regression model. Comparison between the different angles (RCSP, STCA, and HAA) was performed using the Wilcoxon rank-sum test. P values of less than .05 were considered significant.
We found overall almost perfect intraobserver (range, 0.91-0.99) and interobserver reliability (range, 0.74-0.98) for all measures. Mean value and confidence interval (CI) for RCSP and STCA were 10.8 degrees (CI, 10.1-11.5) and 12.6 degrees (CI, 11.7-13.4), respectively. The position of the camera did not influence readings of clinical alignment ( P > .05). The mean HMA was 18.7 mm (CI, 16.3-21.1 mm), and the mean HAA was 23.5 degrees (CI, 21.1-26.0). Clinical and radiographic hindfoot alignment were found to significantly correlate ( P < .05). However, the radiographic HAA demonstrated increased valgus compared to both clinical alignment measurements, with a mean difference of 12.8 degrees from the RCSP (CI, 11.0-14.5, P < .0001) and 11.0 degrees from the STCA (CI, 9.2-12.8, P < .0001).
We found significant correlation between radiographic and clinical hindfoot alignment in patients with stage II AAFD. However, radiographic measurements of HAA demonstrated significantly more pronounced valgus alignment than the clinical evaluation. The results of our study suggest that clinical evaluation of hindfoot alignment in patients with AAFD potentially underestimates the bony valgus deformity. One should consider these findings when using clinical evaluation in the treatment algorithm of flatfoot patients.
Level II, prospective comparative study.
先前的研究表明，成人获得性平足畸形（AAFD）手术治疗时所需的影像学后足矫正量可通过术前存在的影像学畸形量来预测。重建后的成功结果与后足外翻矫正密切相关。然而，尚不清楚后足外翻的临床评估和影像学评估之间是否存在差异。本研究的目的是评估II期AAFD患者后足对线的影像学评估与临床评估之间的相关性。
前瞻性招募了29例（30足）II期AAFD患者，其中男性17例，女性12例，平均年龄51岁（范围20 - 71岁）。以可控且标准化的方式拍摄双侧负重位后足对线X线片。由2名不知情且独立的阅片者测量影像学参数：后足对线角（HAA）和后足力矩臂（HMA）。在后足对线的临床照片拍摄时采用3种不同的垂直相机角度（0°、20°和40°）。由相同的阅片者评估站立位胫跟角（STCA）和静息位跟骨站立位（RCSP）。分别通过Pearson/Spearman检验和组内相关系数（ICC）评估观察者内和观察者间的可靠性。通过线性回归模型评估临床和影像学后足对线之间的关系。使用Wilcoxon秩和检验对不同角度（RCSP、STCA和HAA）进行比较。P值小于0.05被认为具有统计学意义。
我们发现所有测量指标的观察者内可靠性总体上几乎完美（范围0.91 - 0.99），观察者间可靠性也较高（范围0.74 - 0.98）。RCSP和STCA的平均值及置信区间（CI）分别为10.8°（CI，10.1 - 11.5）和12.6°（CI，11.7 - 13.4）。相机位置不影响临床对线的读数（P > 0.05）。平均HMA为18.7 mm（CI，16.3 - 21.1 mm），平均HAA为23.5°（CI，21.1 - 26.0）。发现临床和影像学后足对线显著相关（P < 0.05）。然而，与两种临床对线测量相比，影像学HAA显示外翻增加，与RCSP的平均差值为12.8°（CI，11.0 - 14.5，P < 0.0001），与STCA的平均差值为11.0°（CI，9.2 - 12.8，P < 0.0001）。
我们发现II期AAFD患者的影像学和临床后足对线之间存在显著相关性。然而，HAA的影像学测量显示外翻对线比临床评估明显更明显。我们的研究结果表明，AAFD患者后足对线的临床评估可能低估了骨外翻畸形。在扁平足患者的治疗方案中使用临床评估时应考虑这些发现。
II级，前瞻性比较研究。
