Replacement of Defects of the Femur and Tibia in Revision Knee Arthroplasty Using Non-Biodegradable Materials

In order to restore the function of the knee joint in the terminal stages of arthrosis, primary total knee arthroplasty is used. Primary total knee arthroplasty consists in replacing the femoral and tibial (in some cases, patellar) components of the knee joint with metal and polyethylene (ceramics are used in some types of endoprostheses). This operation has established itself as a method that improves the function of the knee joint in the later stages of gonarthrosis. But in cases of development of aseptic instability of the endoprosthesis components or septic instability of the endoprosthesis components due to periprosthetic infection, it is necessary to resort to revision arthroplasty. During revision arthroplasty, there are frequent cases of the formation of defects in the femur and tibia, which can become an obstacle to stabilization and return of knee joint function. To replace such defects at the present stage, the following methods are used, which relate to non-biodegradable materials: cementing, cementing with screw reinforcement, factory cement spacers with augments, modular metal augments, metaphyseal bushings with pressed porous titanium coating and structural cones made of porous tantalum, megaendoprostheses or individual endoprostheses. This review article analyzes sources describing methods for replacing defects in the bones forming the knee joint during revision knee arthroplasty and consisting of non-biodegradable materials from the PubMed, Google Scholar, SCOPUS, Web of Science databases. The analyzed methods of bone defect replacement are widely used in everyday practice, but also have a number of disadvantages. The use of thick layers of bone cement increases the risk of thermal necrosis and worsens the pressure of bone cement. Factory cement spacers with augment allow only the full defect of the plateau to be replaced. Modular metal augments are associated with corrosion and the development of instability. Metaphyseal bushings and structural cones can cause bone fracture upon insertion and are difficult to remove during revision. Mega endoprostheses or individual endoprostheses are associated with a high risk of infection. Modular metal augments, metaphyseal sleeves, structural cones, mega endoprostheses or individual endoprostheses also have a high cost. At this time, there is a need to develop new methods of defect replacement that will improve the function of the knee joint, improve the quality of life of patients, will be widely available and cost-effective