Background: Treatment of adult tibiofibular fractures, especially severely comminuted fractures, is technically challenging due to the lack of reduction markers and difficulty in restoring the alignment. Fixation of the fibula can facilitate reduction of the tibia fracture and restoration of the lower extremity alignment. Methods: Between 2018-2019 we have operated on 50 patients who have lie on the same plane of tibiafibular fractures. Measures of angulation were obtained from radiographs taken immediately after the surgery, a second time 3 months later, and at 3-month follow-up. The analysis was performed with STATA. Results: Fixating fractures of tibia and fibula at same level were not shown to have complications on the development of nonunion including fibular shortening, hindfoot alignment, slow process of nonunion and unstableness. Conclusions We recommend fibular fixation in all 50 distal fractures when both fractures lie on the same plane and the tibial fracture is relatively stabilized.

Introduction: Air pollution has become one of the major problems in socio-economic and health issues in Mongolia. Among the various hazards of particulate matter (PM) pollutants, microorganisms in PM2.5 and PM10 are thought to be responsible for various allergies and for the spread of respiratory diseases. Recent studies have shown that PM2.5 particles can cause chronic heart failure, heart arrhythmias, and strokes, as well as lung damage, cirrhosis, inflammation, cancer, cardiovascular disease, and metabolic disorders. Furthermore, some studies have concluded that PM2.5 particles in the environment are a risk factor for gastrointestinal, liver, colon, and lung cancer as well as it affects the growth and metastasis of various cancer cells caused by other factors. In our country, the health effects of air pollution and the relationship between the pathogenesis of cancer research are scarce. Therefore, the study of the effects of PM2.5 particles on cancer cell proliferation, migration (metastasis) can provide a significant role for cancer treatment, diagnosis, and prevention. Purpose: Determining the effects of PM2.5 particles on cancer cell proliferation, migration (metastasis) in in-vitro Material and Methods: A human liver cancer cell line (HepG2), human gastric cancer cell line (AGS) were obtained from the central scientific research laboratory in the Institute of medical sciences. HepG2, AGS cells were seeded at a concentration of 1*105 cells/mL in a culture flask and cultured in RPMI-1640 medium supplemented with 10% FBS, 1% antibiotic mix (penicillin, streptomycin) in a humidified atmosphere of 5% CO2 at 37 °C. The cytotoxic effect of PM 2.5 in AGS, HepG2 cells were evaluated by MTT, CCK8 assays. AGS, HepG2 cells were incubated in 96 well plates for 24h then treated with different concentrations (0, 5, 10, 25, 50 and 100 μg ) of Bayankhoshuu, Buhiin urguu, and Zaisan samples for 24h, respectively. Results: Concentrations of 10, 25, and 50 μg/ml of samples collected from the Bukhiin urguu and Zaisan in March increased HepG2 cell growth, while doses of 25, 50 μg/ml of samples collected from Bayankhoshuu in March and December increased HepG2 cell growth. Therefore, concentrations of 25 and 50 μg/ml of samples collected from Bayankhoshuu in March increased AGS cell growth, while concentrations of 25, 100 and μg/ml of samples collected in December increased AGS cell growth. However, no cytotoxic effect was observed in the sample collected from Zaisan in March, whereas the PM2.5 sample enhanced AGS cell growth in dose dependent manner in December.(p <0.05) Conclusion High levels of heavy metals were detected in samples collected in December from Bayankhoshuu, Bukhiin urguu and Zaisan of Ulaanbaatar. Concentration of 25 μg/ml of samples collected from the Bukhiin urguu and Zaisan in March increased HepG2 cell growth. Concentrations of 25 μg/ml of PM2.5 collected from three regions around Ulaanbaatar increased HepG2 and AGS cell migration.