Flexible flatfoot in children: update on surgical treatment and comparison of interposition materials. Porous titanium wedges versus calcaneal autograft and hydroxyapatite.

Paediatric flexible flatfoot is the most common orthopaedic deformity encountered in paediatric practice. Although most cases are asymptomatic and resolve spontaneously, a subgroup of patients develops pain, functional impairment, and progressive deformity, requiring surgical treatment after failure of conservative management. Evans and Cotton osteotomies remain the standard procedures for correcting hindfoot valgus and restoring the medial longitudinal arch, both requiring a structural interposition material to maintain correction. Traditionally, autografts, allografts, and xenografts have been used; however, these options are associated with donor-site morbidity, graft resorption, disease transmission, and potential loss of correction over time. Porous titanium wedges have recently emerged as a synthetic alternative, offering immediate structural stability, osseointegration, and resistance to resorption while eliminating donor-site complications. This review evaluates the current evidence regarding surgical management of paediatric flexible flatfoot, comparing radiological outcomes, functional results, and complication profiles among available interposition materials, and discussing their role in contemporary reconstructive foot surgery.