INTRODUCTION: Flat deformities are one of the most common pathological changes of the feet. Flatfeet is a disease with high social significance, since it not only affects on the quality of life, but is also an important factor in classification of fitness for military service. The main method of diagnosis of these diseases is radiography of the feet in a lateral projection in the standing position. Despite numerous publications describing various methods for assessing the ratio of the bones of the foot, there is no consensus in the scientific community about the exact criteria for flatfoot and its degrees. At the same time, it is noted that the final conclusion is influenced not only by the method of evaluating the finished image, but also by the method of conducting the study. The construction of modern digital X-ray systems in most cases is not adapted for classical X-ray podography, and the study without special devices and the impossibility of strict adherence to the methodology lead to significant distortions of the results. It follows from this that specialized equipment is required for the diagnosis of flatfoot deformities, which allows developing a unified methodology for conducting research and limiting the possibilities of simulations and aggravations.OBJECTIVE: To determine the possibilities of cone-beam computed tomography in the diagnosis of flatfoot deformities in a standing position with a natural load.MATERIALS AND METHODS: This study included 100 patients underwent examination at the S.M.Kirov Military Medical Academy. All patients were examined using the classical radiography and using the cone-beam computed tomograph (CBCT) «ATRISS» (Electron, Russia). Tomograms were evaluated by two methods: using an averaged image and using a thin slice. The study was conducted by two doctors with the determination of the height and angle of the arch of the foot, followed by an assessment of the degree of flatfoot. Statistics. Statistical analysis was performed using Medcalc software (version 18.2.1). The absolute results of measurements for longitudinal and transverse flatfoot obtained by various methods were compared, as well as the time spent on the study (Wilcoxon and Friedman criteria), the degree of correlation between measurements (Spearman’s criterion), as well as the degree of consistency of the conclusions of two experts to identify longitudinal and transverse flat feet (Kappa-Cohen coefficient). RESULTS: Angle measurements in absolute values did not differ significantly between all the methods used (p=0.1803). There were significant differences between measurements of the height of the arch of the foot between the X-ray method and CBCT (p<0.01). In a comparative analysis of radiography and CBCT, two experts noted a high consistency of research results. CBCT made it possible to perform studies with less time (p<0.01). The effective dose for CBCT is significantly higher than for radiography (p<0.01), but does not exceed 0.12 mSv.DISCUSSION: According to the results of the study, it was found that the effectiveness of CBCT in the diagnosis of flatfoot deformities is not worse than classical radiography. At the same time, the CBCT allows you to avoid positioning errors, stacking and cases of attempted simulation. The effective dose for CBCT allows using the technique as a preventive study. Also, CBCT has a high throughput and allows you to get significantly more information in one scan than with radiography.CONCLUSION: CBCT in a standing position with a natural load is not worse then classical radiography techniques in the accuracy of diagnosis of flatfoot deformities. At the same time, the CBCT has extensive postprocessing capabilities, higher throughput, low radiation load, and also reduces the likelihood of methodological errors and cases of aggravation. CBCT is promising in the consciousness of a universal methodology for measuring and classifying of flatfoot with a more precise formulation of setting points for measuring the angles of the arch and deviation of the hallux.
