Radiographic assessment of adult flatfoot.

Abstract

The accurate measurement of flatfoot on standing radiographs allows correct diagnosis of the condition and evaluation of reconstructive procedures. The standing radiographic measurements of patients with symptomatic, adult flatfoot were compared to controls using blinded observers. On the lateral radiograph, the talar-to-first metatarsal angle, the calcaneal pitch angle, and the medial cuneiform-fifth metatarsal height differed significantly between the patient group and the controls. The difference in the talar-to-first metatarsal angles on lateral radiographs was the most statistically significant (patient group 21.1 +/- 10.8 degrees and control 7.1 +/- 10.7 degrees, p < 0.0001) with good correlation between readings (intraobserver 0.75, interobserver 0.83). On the anteroposterior (AP) radiograph, the talar head uncoverage distance was the most significantly different measurement between these groups. These findings support the hypothesis that the talar-first metatarsal angle is an accurate radiographic identifier of patients with symptomatic, adult flatfoot.