A case of congenital annular constricting band syndrome with an open pseudarthrosis of the tibia and fibula is reported. Ischemia, neurological defect and major lymphoedema were present. The child had an emergency treatment combining an external fixator and a one-stage resection of the constricting band. Bone union was obtained within 4 weeks and complete neurological recovery at 6 months. Long-term result, with realignment and normal function, is satisfactory. A review of the literature is undertaken. Amputations are frequent, however pseudarthroses are rare. One-step treatment of the band has been proposed by certain authors. Neurological recovery is usual. The risk of ischemia favors an early surgical treatment.