Abstract
After extraperiosteal harvesting of the fibular shaft in children, progressive valgus deformity of the donor-site ankle may pose a serious problem. We present three illustrative case-histories: three children became functionally impaired and required surgery. Pathogenesis, natural history and surgical options are discussed. A supramalleolar osteotomy combined with a distal fibular-tibial synostosis is a good option to correct valgus and eliminate instability in one surgical session.