The characteristics of stiffness are studied and the fixation means allowable load at fractures of the distal epimetazh of the tibia is calculated. The processes of a fracture points mutual displacements development under the influence of long-term cyclic loads are studied. Metal osteosynthesis was performed using various types of medial and lateral plates with angular stability and blocked plates for fixing fractures in the distal epimetazh of the tibia. The tests are conducted under the influence of actual physiological loads of compression, bending and torsion, including cyclic loading modes.

Purpose. The subject of this work is the experimental substantiation of the contactless method of measuring the movements of bone fragments with the help of digital photography. Design/methodology/approach. During the experiment limbs were used without pathology of bone tissue and tumors on bone tissue. Fixation of bone fragments (osteosynthesis) is performed with the aid of different devices of external fixation. Loading methods: compression, bending and cyclic loading, which simulate the weight of a person. Results. A comparison of the results obtained confirmed the suitability of the method for measuring the displacement of bone fragments with the help of digital photography for practical use. Originality/cost. Results are important for medicine and can improve treatment.

Various methods of measuring the characteristics of stiffness and strength of systems "bone with a fracture - a means of fixation" are considered. Methods for measuring deformations of osteosynthesis systems are systematized, which take into account the nature of the action of external loads and allow to compare different systems of osteosynthesis. The rational arrangement of drugs at tests taking into account features of a structure of bones and the real loadings arising at functioning of musculoskeletal system is recommended. It is proposed to use the stiffness characteristics of the systems "bone - means of fixation" under the action of axial compression, transverse bending and torsion, including in cyclic modes; considered systems of osteosynthesis with the most common methods of fixing fractures to select the optimal in terms of quality methods of fixing fragments in fractures. It is established that the stability indicators of osteosynthesis systems, measured in the process of cyclic tests, are more sensitive to the type of fixing means and can be used to rank these systems according to the degree of mechanical reliability. The results of research obtained using these methods are implemented in surgical practice in the selection of optimal designs of fixation devices and the rational location of fixing elements.

Based on experimental studies, an analytical method is proposed for an estimation of the influence of a regenerate of a bone fabric on rigidity of the system of osteosynthesis. A method for the experimental determination of displacements in the fracture region under the action of loads taking into account the regenerate has been developed and tested. A number of experiments were performed in compression, bending and torsion to determine the deformation characteristics of systems without regenerate and in its presence. The results of experiments related to the influence of bone regenerate formed during the fusion of fractures on the mechanical characteristics of the system "bone with a fracture - a means of fixation" are described. To assess the impact of bone regeneration, a method for studying the deformation of osteosynthesis systems using the method of modeling bone regeneration with a polymeric material with specified properties was developed and implemented. Using the stiffness condition, the expression for the calculation of permissible loads that do not lead to dangerous displacements of fracture points is obtained. The reduced deformations and permissible loads for the systems "bone with a fracture - a means of fixation" at different stages of bone tissue (ВT) regeneration under the action of compression, bending and torsion are calculated. It is established that the formed regenerate significantly increases the rigidity of the system "bone with a fracture - bone regenerate - a means of fixation", which increases the level of allowable loads on the extremities at different stages of treatment. Test and calculation data can be used to improve methods of treatment of damaged limbs in the intermediate and final stages of fracture fusion.

Functional reliability of fixative-bone means was studied for various types of metacarpal fractures depending on the type of fixator and its location. The stiffness characteristics of fracture fixation systems with titanium miniplates were studied, an analysis was performed of the surgical treatment of patients with metacarpal fractures, in which osteosynthesis with needles and external fixation rod apparatus was used, with static and cyclic modes of action of external loads. When transferring a compressive force to a fragment, the type of fixing means significantly influences the deformation of the osteosynthesis system at all levels of stress; for the most of the measured characteristics, rod devices with external fixation and titanium miniplates of various designs are preferable.