Objective – to compare the results and complications of open wedge high tibial osteotomy (OWHTO) in patients operated on according to the standard technique and using the developed method of performing the operation using the original fixator.Materials and methods. 73 patients with primary and secondary OA of the knee I–III stages were recruited into the study, which were divided into 2 groups. Group 1 consisted of 43 patients, who underwent 46 OWHTO from 2005 to 2019 using the standard technique using short plates with a fixed spacer (Puddu I (5 times) and II generation (24 times), Osteomed (17 times)) and bone grafting. Group 2 consisted of 30 patients who were operated on in 2018– 2020 using the developed surgical technique and the original fixator. To assess the result, we studied the change in pain according to the Visual Analog Scale (VAS), as well as the functional (FS) and objective scores (OS) of the knee according to the Knee Society Score (KSS) before surgery, after 3 months and 1 year after OWHTO.Results. In group 1, one year after OWHTO, the results were obtained: excellent in 43.5% of cases, good – in 41.0% and satisfactory – in 15.2% of patients. In group 2, an excellent result was obtained in 59.3% of patients, good – in 33.4% and satisfactory – in 7.3% of cases. In group 1, 15 (32.7%) patients were diagnosed with 26 complications, and in group 2 – 5 (16.6%) patients with 5 complications.Conclusions. The use of the developed surgical technique and the original fixator made it possible to increase the percentage of excellent and good treatment results from 84.5% to 92.7% and to reduce the number of complications associated with OWHTO from 32.7% to 16.6%.