Characterization of bone tissue changes in the zone of defect under disordered reparative regeneration

Purpose. The evaluation of morphological changes in the bone tissue of defect zone under disordered reparative regeneration. Materials and Methods. The study performed on laboratory animals - Chinchilla rabbits. All the experimental animals underwent modeling the conditions of disordered reparative regeneration. Radiological and morphological changes in the zone of bone defect evaluated in the study dynamics. The technique of gamma scintigraphy used for evaluation of morphofunctional changes in the zone of bone defect. Results. The delayed juxtaposition of fragments by Day 14 established to lead to marked morphological changes in the zone of defect by Day 20 of the study, with pseudoarthrosis formation by Day 50. During histological investigation the formed cavities revealed the walls of which were formed with hyaline cartilage, with observed enchondral ossification of callus underlying spongy bone, with collagen fiber foci and sites of spongy bone structure. The predominance of connective cartilaginous tissue and bone tissue ratio was 1:1. As it was established by bone scintigraphy technique, radiopharmaceutical accumulation in the zone of bone defect increased in phase 2 and 3 in the left limb thereby evidencing of the maintaining active reparation processes up to Day 50. Conclusion. The disordered conditions of reparative regeneration as 14-day delayed juxtaposition of bone fragments lead to pseudoarthrosis formation by Day 50 of the study.