EFFECT OF TERAHERTZ RANGE ELECMAGNETIC WAVES ON DISTRACTION OSTEOGENESIS BY TIBIAL DEFECT FILLING IN THE CONDITIONS OF TRANSOSSEOUS OSTEOSYNTHESIS (EXPERIMENTAL STUDY)
The experiment was carried out on 12 adult mongrel dogs. Defects were modeled in the lower third of the tibia and measured 3 cm (16,3 ± 0,3 % of the segment length). Next, osteotomy at the level of the proximal metaphysic was produced. Distraction was initiated after seven days with the rate of 1 mm a day made with four steps that continued 30 days for transporting the osteotomised fragment into the defect. One group (n = 8) had local stimulation with electromagnetic waves of terahertz range at the level of distraction regenerate from the 25th day of distraction. Control animals did not receive stimulation. By the end of distraction, the regenerated bone featured zonal structure by the middle of distraction period that was proven radiographically. Bone portions of the regenerates were mostly presented by endosteal homogenous shadows. Zonal structure was radiographically seen in both groups by the end of distraction. Bone portions of the regenerate were 8,7 ± 0,3 mm high and were of homogenous structure. The middle transparent zone was crossed by singular trabecular «bridges» in the centre and on the periphery. In the group of electromagnetic stimulation, the fixation time was 50,6 ± 2,7 days as compared to 75 ± 8,7 days in the control group. Distraction regenerate density studied with CT by the end of fixation in the Ilizarov apparatus was 439,4 ± 127,8 and 389,9 ± 46,3 HU, respectively. The cortical plates of the regenerated bone had a higher density in the first group than in the control one, 755,8 ± 54,7 and 688,75 ± 66,3 HU respectively. These findings showed that electromagnetic waves of terahertz range had a stimulating effect on the formation of the regenerated bone in the management of post-resection tibial defects with the Ilizarov method of non-free autograft transporting. It contributed to the formation of a mechanically strong regenerate in a shorter period of time.