The possibility of using contact ultrasound impact under transosseous osteosynthesis (an experimental study)

Purpose. To study the effect of low-frequency ultrasound on the thermodynamic and diffusion processes in long tubular bones in order to have the possibility of using contact ultrasound impact on bone and its combining with transosseous osteosynthesis. Materials and methods. The study was conducted as a poster experiment using cadaver segments of animals’ long tubular bone. We used pins made on the basis of an external fixator half-pin, inserted in the bone as waveguides (a standard half-pin, an entire pin-waveguide, a hollow half-pin with inserted waveguide). The features of waveguide-bone thermodynamic interaction were determined, as well as diffusion processes in bone induced by ultrasound. All the material was divided into six (6) equal groups and a control group depending on waveguide type and fixation technique. Results. The temperature at bone-waveguide interface was 45-55°, diffusion processes: 9.92 mm (monocortical fixation), 23°, 1.1 mm (bicortical fixation), respectively, - in the groups with a standard half-pin (1 and 2); 79-99°, 39.8 mm (monocortical fixation), 65-99°, 35.7 mm (bicortical fixation) - in the group with an entire pin-waveguide (3 and 4); 35-45°, 28 mm (monocortical fixation), 23-34°, 10 mm (bicortical fixation) - in the group with a hollow half-pin (5 and 6). Conclusion. The use of a half-pin and its modifications as waveguides for contact ultrasound impact induces thermodynamic and diffusion processes in the bone.