The article presents the results of surgical rehabilitation of patients with fractures of the humerus diaphysis using transosseous osteosynthesis with an external fixation device in 21 patients with diaphyseal fractures of the humerus, with localization in the middle-lower third of the diaphysis, on the example of clinical cases. Evaluation of the results of the study was carried out by retrospective analysis of the outcomes of surgical rehabilitation of patients with fractures of the humerus diaphysis using transosseous osteosynthesis by external fixation apparatus in the period from 2015-2020, which showed that modified closed transosseous osteosynthesis by external fixation apparatus, the use of a rod line-up allows to significantly reduce the risks of complications in comparison with the traditional technology of bone and intraosseous fixation and allowing to achieve excellent and good results in 85.7% of patients with diaphyseal fractures of the humerus.