External fixation is a high-tech procedure in the treatment of patients with orthopaedic and traumatologic profiles. Consequently, the type of transosseous elements (K-wires, S-screws, half-pins) and their levels and their passing positions, the levels of the external supports of the fixator, and the biomechanical relationship between the supports must be strictly regulated (standardized) [1, 2]. Text annotations, even accompanied by explanatory figures, are grossly inaccurate because they leave too much room for data interpretation. The resulting three-dimensional image achieved using this computer technique is by far the most precise application; however, it is very expensive and laborious to create models for all situations considered in external fixation. With a minimal number of symbols, the method of unified designation of external fixation (MUDEF) of long bones provides a comprehensive system for the following: the type and the spatial orientation of transosseous elements, the order and the direction of their passing, the form (geometry) and the dimensions of external supports, as well as the biomechanically indicated relationship between the supports, etc. [3]. Additionally, MUDEF provides: - A unique possibility of studying the method of external fixation [4, 5]. Using MUDEF in instructional course lectures,monographs, manuals, and original articles, the entire algorithm of the operation can be accurately recorded and failure of the method avoided due to inaccuracies and mistakes during its implementation. - A basis for eliminating pin-induced damage of neurovascular structures. In Germany, Italy, the USA, and Russia, atlases have been published that identify the schemes of the transverse cuts of the extremities and the designated sectors where it is dangerous to pass K-wires and half-pins. Using the coordinates of the present method in combination with any of the mentioned atlases significantly facilitates the defining of dangerous sec tors and safe corridors during surgery [4, 6]. - Facilitation of routine work during the recording operations of external fixation with a simultaneous increase in the self-descriptiveness of performed records. - Accuracy and comprehensiveness of corresponding consultations (including teleconsultations) [7].With MUDEF data for the recommended configuration of an external fixation device for a specific case can be exchanged during online conferencing/consultations. - Facilitates simultaneous maintenance of computer databases with optimal configurations of external fixation devices for different kinds of orthopaedic and traumatological pathological conditions. - The possibility of estimating and describing in detail external fixation complications. For example, pin-tract infections are often seen in external fixation. The use of MUDEF helps define the levels and the projections of those positions where pin-tract infection appears most frequently. The same principle can be used to define the transosseous elements causing pain or limiting the range of motions of the joints, etc. - A basis for the unification of scientific research on improving external fixation devices. The most important characteristics of the devices for external fixation are the possibility to change the spatial orientation of bone fragments (reduction), rigidity of fixation, and to provide extremity function. During development of generally accepted criteria of each characteristic, specific configurations of external fixation devices can be compared by applying MUDEF in order to select the optimal ones. - Accuracy in describing a local area is increased: place of punctures, cuts, installing of the drains, etc. - Helps overcome language barriers among orthopaedic surgeons in different countries and establishes a universal international code for describing external fixator constructions.