Sequestrectomy, fragment fixation, wound treatment and bone grafting are the old principles of infected non union surgery. Today these principles are the frame, which contents a more aggressive treatment. Sequestrectomy is a radical excision of the complete infected bone-soft-tissue-scar, the resulting defects are covered by one of the various techniques (skin-traction, flap surgery, bone shifting, etc.). Out of 71 infected non unions, treated by radical resection and bone segment transport, healing rate without recurrence of infection was 94%, in 3 additional patients (4%) amputation was performed. For bone fragment fixation, a non devastating implant, like external fixateur, is preferred. To close the wound, the law of avoiding a dead space is used. Defects are closed by muscle flaps, by fragment shortening or by a antibiotic spacer temporarily. The skin is closed by skin-traction techniques or with flap surgery. After soft tissue healing, small bone defects are filled by autografts, defects of more than 3-4 cm with transported segments. Previous limb shortening to close bone defects, with a lengthening later in a "healthy" region, is also possible. Local antibiotic wound treatment cases a significant reduction of the contamination rate, improved dressing techniques support wound healing free of infection. This therapeutic techniques are comparable to open fracture treatment, where by similar surgery a very low infection rate can be achieved.