The aim is to study the possibilities of modern reconstructive traumatology and orthopedics in the replacement of large–scale defects of the musculoskeletal system.
Materials and methods of research. Analysis of modern scientific literature on this topic.
Results. 3D-printed implants have proven themselves positively in reconstructive traumatology and orthopedics with good functional results [11], which is ensured by high anatomical compliance of the removed segment, bioneutrality, biodegradability, versatility, adaptability, the possibility of using various fixation methods and the speed of production.
The wide range of currently used materials for bone grafting indicates the need to develop new materials.  For successful application, it must have the following characteristics: osteoimplantation, osseointegration, osteoconduction, osteoinduction, osteogenicity [10].
The technique developed by G.A. Ilizarov is a treatment for bone deformity based on the use of an external orthosis and subsequent fixation in the desired position for their further recovery [8], is a highly effective approach to solving orthopedic problems, allows us to consider a bone graft as an optimal design in terms of vascularization, size and shape [20]. Despite the high reliability of the method, its use is associated with certain limitations for the patient. In this regard, alternative methods have been proposed. In most cases, closed blocking intramedullary osteosynthesis is used, since this reduces the risk of blood loss and soft tissue damage [1, 9].
Porous titanium implants are a promising material for bone replacement in various fractures accompanied by the formation of large defects. Due to their properties, they are capable of full integration with bone tissue [13].
Conclusion. 3D modeling has great potential in the field of endoprosthetics, subject to optimal indications. This method is a process of creating three-dimensional virtual models. One example of the use of 3D printing is the development of individual implants, models of anatomical structures that help surgeons better understand the specifics of a particular case and plan the operation in advance. Currently, metallic, inorganic, nonmetallic, and polymeric materials are used for 3D printing of bones [16]. Nevertheless, this method requires further research and increased patient follow-up [6].
The gold standard of bone grafting is auto-hardness, but since it cannot be used in certain cases, alternative materials of allogeneic, xenogenic or synthetic origin are used.
The development of osteosynthesis implies not only the improvement of implantation technologies, but also a deep understanding of the processes of bone tissue regeneration under surgical intervention [17]. Osteosynthesis can be considered as a controlled process of reparative regeneration, however, the implant itself is not capable of providing fracture healing [1, 14].