How Accurate Is Clinical Evaluation in Hindfoot Coronal Alignment?

Abstract

Background: Hindfoot coronal alignment is an important factor in the assessment of patients with many different foot and ankle complaints. A number of clinical and radiographic techniques have been described to measure hindfoot coronal alignment, but none of them are widely accepted. The purpose of the present study was to assess the correlation between clinical and radiographic hindfoot alignment measures and to evaluate the reproducibility of each. Methods: We evaluated 85 patients with foot and/or ankle symptoms. Hindfoot clinical alignment was measured from photographs. Each patient was placed at a distance of 1 m from the observer, with both feet placed parallel. Four photographs were taken, at a height of 40 cm: a posterior view of both lower limbs including knees, a posterior view focalized on the studied hindfoot, an anterior view of the foot, and the last view of the medial aspect of the foot. Radiographic alignment was quantified on long axial view radiographs. Patients were lying over the film cassette with a focus distance of 1 m and the beam pointed to the ankle joint. The inclination angle of the beam was 45 degrees to the floor. Measurements were independently made by 2 observers, who were asked to classify pictures into 3 categories: varus, neutral, and valgus. Radiographic measurements were made using the angle measurement tool on the radiograph viewer. The intraclass correlation coefficients (ICCs) and the 95% confidence interval (CI) of the ICC were used to quantify the inter- and intraobserver reliability for clinical assessment. Radiographic parameters were correlated by calculating the Pearson correlation coefficient (r). Results: The intraobserver ICC for clinical analysis was good for both observers, while the interobserver ICC was moderate for both measurements. Regarding radiographic assessment, there was significant intra- and interobserver reliability. The correlation between both methods was weak for both observers. Conclusions: We found only weak intra- and interobserver correlations between the clinical and radiographic assessment of hindfoot coronal alignment. It is therefore necessary to complement the clinical evaluation of hindfoot alignment with an objective measurement method such as a long axial view radiograph. Further studies comparing different measurement methods need to be performed to establish the most objective evaluation. Level of Evidence: Level III, diagnostic study.