Summary. The complications, reported most frequently by physicians are: additions of an infection, impaired fracture union processes, the occurrence of persistent joint contractures, especially after intra-articular fractures. Mechanical-related complications associated with bone-fixing devices are of particular importance. The information mechanical complications in the literature is rather controversial. Particularly debatable is the identification of any specific backgrounds of these complications. Virtually no attention is paid to the behavioral or social aspects of the issue, and the quality of the rehabilitation regime. Objective. Analysis of the background of the complications after surgical treatment, associated with mechanical factors, and identification of the means able to prevent them. Material and methods. The results of treatment of 36 patients operated on for fractures of their extremities, who had complications related to the inadequate mechanical fixation of their broken bones. The onset of complications ranged from 5 days to 1 year from the date of surgery. All patients were divided into 2 groups: Group I (iatrogenic) - 10 patients with iatrogenic complications; Group II (patient-dependent) - 26 patients with clearly identified patient-dependent disorders. Results. There were 15 fractures of a retainer (or its elements) and 21 cases of migration or deformation of structures. The most problematic segment was the proximal thigh, which, in our opinion, has a clear age dependence. Analyzing the errors of surgical treatment (group I), we have assumed that they could be prevented by the timely correction of postoperative complications. The prescribed treatment regimen was violated in 72,2% of cases (group II). 13 patients (50%) reported a repeated trauma in the early post-operative period. Conclusions. Prevention of mechanically-induced complications should be based on the adherence to surgical protocols, dynamic observation of the patients in the post-operation period through tight relations with the outpatient unit, considering both somatic and psychological criteria, and timely correction of the treatment regimen.