Background. The article deals with extra-articular fractures of the distal humerus, according to the АО/ASIF classification, which includes types 12A–C, depending on the plane of the fracture and the nature of the fragment displacement. The purpose was to study the features of the lower third humeral fractures and to conduct a comparative analysis of the outcomes of surgical treatment. Material and methods. One hundred and twenty-seven patients with extra-articular fractures of the distal humerus were under observation. For retrospective analysis, they were divided into a comparison group (n = 92) who underwent traditional bone osteosynthesis and a study group (n = 35) in whom a rod-type external fixation device developed by us was used. The short- and long-term functional results were studied using the Mayo Elbow Performance Score. Results. Various indicators, established by us for comparison, and treatment outcomes were analyzed in 101 patients (comparison group — 68 people, study group — 33). Many values of these parameters were quite comparable in terms of the age, gender, hospitalization terms, duration of surgeries, etc., but the revealed differences in indicators still did not reach the level of statistical reliability (p > 0.05). Evaluation of the clinical use of the device proposed by us showed restoration of the humeral anatomy, quite comparable to that in bone osteosynthesis, and the achievement of the final result of treatment. However, the number of complications by type and by total number was significantly higher (4.5 times; p ˂ 0.001) in the comparison group, where it accounted for the largest share of cases of neuropathies (16.18 %), nonunions (8.82 %), elbow contractures (8.82 %) and heterotopic ossification (4.42 %). The final score on the Mayo Elbow Performance Score in the comparison group was 84.9 ± 10.2 points, in the study group — 92.6 ± 3.7 points. At the same time, the total number of positive treatment outcomes after bone osteosynthesis was 66.18 %, after transosseous osteosynthesis — 81.82 %. Conclusions. The analysis of the data obtained allows us to recommend a method of minimally invasive osteosynthesis with a rod device of external controlled fixation as a method of choice for wider clinical use in the treatment of patients with lower third humeral fractures.