Study of physical and mechanical properties of polymer-impregnated composition in clinical purulent osteology

Bone cement, or PMMA (polymethyl methacrylate) is often used in purulent surgery. Scientific literature contains very contradictory data on the physical and mechanical properties of polymer-impregnated compositions, in particular, on the temperature of the PMMA polymerization process and the ways to reduce it, such as introduction of antimicrobial drugs for prevention and treatment of infectious complications in patients after injuries and musculoskeletal surgery. The aim of the study is to conduct an in vitro experiment and to evaluate the temperature of the exothermic polymerization reaction of bone cement (PMMA) and possible ways to reduce it. Materials and Methods. The authors conducted 8 series of experiments in vitro. In each series, a disk (45-50 mm in diameter, 5-7 mm thick) was made by hand after mixing the components of the polymer composition. The temperature of the ongoing exothermic reaction was measured on the disk surface using a non-contact infrared thermometer ADA TemPro 300 in a continuous scanning mode. Results. The temperature of the exothermic polymerization reaction of PMMA Synicem 1 -based bone cement was 92.8±1.6 °C (min 91.2 °C, max 94.9 °C), and Palacos®MV+G-based bone cement 92.7±1.2 °C (min 91.1 °C, max 93.8 °C). Reducing the monomer amount by 50 % (polymer/ monomer ratio was equal to 4:1) and simultaneously introducing “Sextaphage" (10 ml) led to a sharp temperature decrease of the exothermic reaction by more than 30 °C. Conclusions. One of the ways to reduce the temperature of the exothermic reaction in vitro is to change the ratio of polymer powder and liquid monomer, reducing the amount of monomer introduced into the polymer composition.