Flexible flat foot is considered one of the commonest normal variants in children's orthopaedic practice. The weightbearing foot is usually regarded as flexible on the basis of results from clinical and radiographic examination as well as measured foot-ground pressure pattern. Our aim was to compare the pedobarographic and radiographic findings of normal arched and symptomatic flexible flat feet and investigate if there were sensitive markers that could be used in selecting patients for surgical correction. We retrospectively collected data from eighteen patients (ten to sixteen year old). Our control group consisted of ten patients (twenty feet) with normal arched feet and the study group of eight patients (fifteen feet) with symptomatic flat feet who were awaiting surgical correction. The mean and standard deviations of three radiographic markers (Calcaneal pitch, Naviculocuboid overlap and lateral Talo-1st metatarsal angle) in addition to foot pressures measured at the hindfoot, medial/lateral/total midfoot (MMF, LMF, TMF), forefoot and the percentage of weight going through the MMF over the TMF (medial midfoot ratio (MMFR) during the mid-stance gait phase are reported. In addition, the sensitivity, specificity, positive predictive value and negative predictive value of the pedobarographic parameters were estimated. There was a significant difference in the Naviculocuboid overlap (P<0.001 T test) and Calcaneal pitch (P<0.05 T test) between both groups. The flat feet group had significantly higher MMF, LMF, TMF and MMFR (P < 0.001 Mann-Whitney). LMF had the highest sensitivity and negative predictive value (94%) whereas MMF, TMF and MMFR had the highest specificity and positive predictive value (100%). Compared to our control group, patients with symptomatic flexible flat feet had significantly higher pressures distributed in the midfoot, in particular in the medial midfoot. Pedobarography appears to be a sensitive and specific tool that can be used, in conjunction with clinical and radiographic findings, in diagnosing flat feet. Our study suggests that pedobarography could be used to measure the degree of deformity before and after surgical intervention.
