Reliability of hindfoot alignment measurements from standard radiographs using the methods of Meary and Saltzman.

BACKGROUND: Few methods have been described for measuring hindfoot alignment from an anteroposterior view. The objective of this study was to compare two methods of angular measurement based on the views of Meary and Saltzman.

METHODS: Thirty asymptomatic volunteers were included. Four radiographs were performed: the views of Meary and Saltzman with parallel feet and with the Fick correction. The reproducibility was determined by the inter- and intraobserver variability (ICC).

RESULTS: Meary's method revealed a mean valgus angulation of 3.9° (SD 3.47°). The reliability was extremely variable with a mean ICC of 0.59. The best reproducibility was obtained with Meary's method with and without Fick correction.

CONCLUSION: The results of this study show that the reliability of the angular measurements depends on the radiographic view and measurement method chosen. The lateral Fick correction did not counteract the influence of tibial rotation. The same method should be used consistently.