The blocking osteosynthesis is preferable in the case of open forearm fractures of the I degree. The treatment of patients with open comminuted complicated forearm fractures should be reasonable to perform in two stages: at the first stage, healing of soft tissues with fixation in the apparatus of external fixation should be obtained. At the second stage, the conversion of external fixator on interlocking nail with single-stage performance of osteoplasty as needed should be carried out. The presented experience of treatment of healing failure, pseudoarthroses and forearm bone defects by developed method allows the practical application of the method to be recommended.