The mechanical properties of the system bone-implant systems

Fractures of the diaphysis of leg bones make up 45 % of all long bone fractures, they are one the most common injuries to the bones of the limb segments, the treatment of which is accompanied by a large number of complications, therefore the problem of improving the treatment of patients with this injury is still relevant for present traumatology and orthopedics. The use of compression distraction systems, intramedullary and extramedullary osteosynthesis systems allows a stable functional osteosynthesis and eliminates the need for additional gypsum immobilization of a segment or limb in the postoperative period. Biomechanical relations in the bone-implant system in conditions of a stable functional osteosynthesis constitute an important factor allowing to objectify the mode of motion rehabilitation in the early postoperative period. This work studies the results of the comparative bench tests of groups of cadaver tibia in experimental injuries of type 42 A 1.1. (according to the Association for Study of Internal Fixation ( AO / ASIF) ) synthesized with different types of implants, such as Fixion expanding system of fixation, external fixation devices, limited contact dynamic compression plate (LC-DCP) and blocked intramedullary osteosynthesis system (BIOS)). Each system was axially compressed using INSTRON 1185. Resistance to axial compression has been analyzed. It is noted that all these types of fixations increase the strength of the systems in the range of 22-81 % compared to the intact specimens. Intraosseous fixation systems demonstrated the highest strength, which has the most optimal biomechanical relations in the bone-implant system, allowing to objectify the regime of motion rehabilitation.