Introduction. Fixation of the acetabular component in patients with bone defects of the acetabulum is a difficult task due to the insufficient quantity and poor quality of the remaining bone tissue. During the last few years in our country in arthroplasty of the acetabulum with severe bone defects were actively used implants made of trabecular metal. Purpose of study: was to evaluate short-term clinical and radiological results of the usage of trabecular metal components in patients with bone defects in revision and primary hip replacement. Patients and methods. 59 surgeries were performed using components of trabecular metal, 53 of them were performed on the instability of the hip prosthesis, 2 - post-traumatic hip dysplasia, 2 - aseptic necrosis of the femoral head, 2 - high dislocation of the femoral head. Among the operated there were 37 women and 22 men, the average age was 58.2±19.9 years. According to the Paprosky classification, defects in 12 cases corresponded to type IIA, in 14 - type IIB, in 6 - type II, in 19 - type IIIA, in 7 - type IIIB. The structural features of these implants, made of tantalum in a carbon skeleton with uniform porosity, similar to the structure of bone tissue, provide an increased coefficient of friction, thereby contributing to the rapid growth of bone tissue in the implant structure. Results. The average follow-up period was 14 months. The average preoperative assessment of the hip joint by Harris Hip Score (HHS) was 43 points (from 14 to 86). After surgery, the average HHS improved to 88.7 (69 to 100). 1 patient had hemorrhagic discharge after surgery. On the 7th day an audit was performed. In 2 cases, paresis of the peroneal portion of the sciatic nerve developed after surgery. There were no cases of recurrent dislocations, deep infection, pulmonary embolism or death as a result of operations. Conclusion. Taking into account the mechanical properties, tantalum implants allow to achieve a stable primary fixation with the restoration of the center of rotation of the hip joint and eliminate the risks associated with the use of allografts. Conflict of interest: the authors state no conflict of interest Funding: the study was performed with no external funding

The main advantages of the М2а-Magnum modular system pair are the presence of a group of metals metal with wear of the large head, which is the maximum value that makes it possible to increase the range of motion in the hip joint by more than 160 with virtually no risk of dislocation [1]. This allows you to freely conduct active work and sports. However, the system is not without drawbacks. First of all, this is the unrevealed danger of damage to metal ions in the blood, as well as the problem of the development of a pseudotumor lymphoid reaction [2,3], leading to extensive osteolysis, an increased risk of periprosthetic fractures, and, accordingly, an increase in the frequency of endoprosthesis destabilization. Currently, the use of constructions is practically suspended, but there are more than 1 million patients in the world [4] with implanted large "metals - metal pairs". In revision surgery with M2a-Magnum implants, the main problem is often the inability to remove the femoral head adapter component from the neck taper. fretting corrosion is observed, leading to the effect of cold welding. The latter is typical for the connection of titanium surfaces (adapter of the head module and the neck of the femoral component). It turns out that it should be noted that the M2a-38 system does not have a titanium adapter made of a cobalt-chromium alloy and devoid of this problem [4].

Relevance. Fractures of the patella represent about 1% of all fractures of the bones. Among surgeons there is no a single approach to the treatment of patients with many fragmentary patellar fractures. After surgical treatment of patients with patellar fractures, various complications could be observed. Aside from that, there is no consensus on the treatment of complex fractures of the patella, and in practice, trauma physicians use a variety of methods of osteosynthesis of the patella. In the light of the foregoing, the study of long-term results of patients after patellar fractures is of particular relevance. Purpose of study: to examine the results of patients after surgical treatment of patellar fractures with a view to devising best practices for its osteosynthesis. Patients and methods. A study of the results of treatment of 78 patients with patellar fractures was conducted. The following groups were identified depending on the type of surgery and the nature of the fracture: Weber osteosynthesis in fragmentary fractures; «cruciform osteosynthesis» and other identical options of osteosynthesis with spokes and wires at three or more fragmented fractures of the patella; combination osteosynthesis. A comparative analysis of the results of treatment of patients after partial patellectomy and osteosynthesis of the patella with spokes and tightening wire loops was conducted. We evaluated the results on the KOOS scale with clinical examination and x-ray examination of patients. Beyond that, we have supplemented this scale with the patients’ own opinion on the evaluation of the results of their treatment. Results. The average follow-up period was 22 months. A comparative analysis of the groups of patients after surgical treatment of patellar fractures on the KOOS scale showed the best results in osteosynthesis of transverse two-fragment patellar fractures by Weber’y - 72%. The results of treatment of patients with many fragmentary patellar fractures using 3-5 spokes and 2-3 wires was - 64%; after the rehabilitation of the lower pole was - 68%) and after partial patellectomy -51%. Conclusion. If a patient has three-fragmented patellar fractures, reasonable results could be achieved by using 3 spokes and 2 tightening wire loops. With four or more fragmentary fractures of the patella, the optimal method for its osteosynthesis is the use of a «cruciform» method with 4 or more spokes in combination with two or three wire loops. The use of patellectomy with subsequent fixation of the blocking wire loop should be avoided in all types of patellar fractures. Key words: patellar fracture, osteosynhesis, surgical treatment Conflict of interest: the authors state no conflict of interest Funding: the study was performed with no external funding