Aim. To define relations between serum concentrations of sRANKL and BMP-2, IL-1, TNF, IL-4 as well as their role in endoprosthesis instability pathogenesis in patients following primary knee arthroplasties. Materials and Methods. 80 patients were retrospectively divided into 2 groups: there were 40 patients with osteolysis and aseptic instabilities of knee endoprosthesises that had developed before 12 months after the surgery in the 1st group; the 2nd group was made up of 40 patients with implantat-associated inflammations that had developed in 4 weeks to 12 months after primary knee arthroplasties. 20 volunteer donors made up the control group. The enzyme-linked assay was used to define serum content of sRANKL (pg/ml, Biomedica, Austria), BMP-2 (pg/ml, Ray Bio, USA), cytokines TNF (pg/ml), IL-1 (pg/ml) and IL-4 (pg/ml) (Vector-Best, CJSC, Novosibirsk, Russian Federation). The comparative analysis of statistically significant indicants was performed defining Spearman rank correlation coefficient. Results. Positive statistically valid relations of average force between concentrations of sRANKL and BMP-2, TNF, IL-4 were found in patients of the first group in 1 month after surgeries. In 12 months positive relations of the parameters under study subsisted although the relation with IL-4 absented. The emerging of moderate negative statistically significant relations of sRANKL with BMP-2 and TNF was observed in patients of the 2nd group in 1 month after surgeries. In 12 months negative relations of average force between sRANKL and BMP-2 subsisted, also new moderate relations emerged: negative relation of BMP-2 with IL-1 as well as positive of sRANKL with IL-1 and TNF, IL-1 with IL-4. Conclusion. We found that the disorder of metabolic processes in bone tissue surrounding the implantat with the predominance of osteoclastogenesis activating pro-inflammatory cytokines might be the pathogenic factors of endoprosthesis instability development in patients following primary knee arthroplasty.

Aim. To study peculiarities of macrophage reaction and humoral immunity in patients with signs of implant-associated inflammation after the primary endoprosthetics of the knee joint. Materials and Methods. Examination of 48 patients with signs of implant-associated inflammation after the primary endoprosthetics of the knee joints (the main group) and of 44 patients without signs of inflammatory reactions (comparison group) was carried out. Control group involved 30 healthy donors without diseases of the musculoskeletal system. Results. In 1 and 12 months after the surgery, patients of the main group showed elevated levels of the factor inhibiting migration of macrophages (MIF), of macrophage stimulating protein (MSP), class A immunoglobulins (IgA), С3 and С4 complement components as compared to control, and also to each previous period. In 1 month after the surgery, the content of class M and G immunoglobulins (IgM and IgG) decreased relative to control; in 12 months after the surgery a more pronounced reduction was noted. Increase in serum concentrations of MIF, MSP, IgA, С3 and С4-complement components was noted in the comparison group in 1 and 12 months and also in comparison with the previous period. Reduction of the levels of IgM, IgG in 1 and 12 months after the operation was noted in comparison with control and with the previous period. Conclusion. A study of parameters of macrophage reaction, proteins of complement system and the main classes of immunoglobulins permits to identify signs of implant-associated inflammation in 1 and 12 months after surgery, and, consequently, to determine patients of risk groups that require additional diagnostics measures.

Aim. To assess the separate indices of blood serum bone tissue metabolism content in patients with instability of prostheses after the primary knee joint arthroplasty. Materials and methods. The main group joined 40 patients with implant-associated inflammation, the comparison group – 40 patients with primary aseptic instability of prostheses, the control – 20 conditionally healthy donors. The blood serum hPTH and 25-OH Vitamin D content was determined using solid-phase immune-enzyme assay. Results. Among the patients of the main group, blood serum hPTH concentration increased as compared with the control after1 and 12 months following the surgery and compared with each previous observation period; 25-OH Vitamin D level decreased compared with the control before the surgery, after1 and 12 months following the surgical intervention and compared with each previous period of observation. In the patients of the comparison group versus the control values, blood serum hPTH concentration elevated and 25-OH Vitamin D level declined after 1 and 12 months following the surgery and compared with the previous observation period 1 month later. Conclusions. When estimating the blood serum hPTH and 25-OH Vitamin D content in patients with instability of prostheses after the primary knee joint arthroplasty, there were revealed multidirectional changes in their levels, showing bone tissue metabolic disorders.