Does the long-term use of medial arch support insole induce the radiographic structural changes for pediatric flexible flat foot? - A prospective comparative study

Abstract

Background: Several conservative treatment methods, from intrinsic muscle exercises to orthoses, including insoles or specially designed shoes, have been introduced for pediatric flexible flat foot (PFFF). However, the structural effects of a long-term use of medial arch support insole remain unclear because the normal physiological maturation of the medial longitudinal arch cannot be ruled out.

Methods: From January 2005 to June 2015, 18 patients (34 feet) in group 1 (continuously insole applied group) and 13 patients (26 feet) in group 2 (untreated group) were enrolled. Medial arch support insole was applied from the age 10-11years to radiographic physeal closure.

Results: In group 1, talonavicular coverage angle, lateral talo-1st metatarsal angle, calcaneal pitch angle and medial cuneiform height were significantly changed at final follow-up, although all values were still within the abnormal range. Further, no significant differences were found in any of the increments of the radiographic parameters between group 1 and 2.

Conclusions: Radiographic improvements were found in both of medial arch support insole treated or untreated group despite all radiographic values were still within the abnormal range. It was meaningful that the PFFF could be improved somewhat until the physes were closed. And the hindfoot alignment remained unchanged regardless of medial arch support insole application.

Keywords: Flexible flat foot; Medial arch support; Natural course; Orthoses; Pediatric flat foot.