Histomorphometry as a method for assessing the healing of tubular bone fractures

Aim – to carry out a quantitative assessment of the healing of tubular bone fracture modeled by applying a hole defect in it and to analyze existing methods of bone regenerate morphometry. Material and methods. The data were obtained on 30 white mature rats, which had a hole defect made in the tibiae. Morphological and morphometric studies of the regenerate were performed on the 3rd, 10th, 15th, 24th and 45th days after surgery on histological sections. Results. Microscopically the tibial regenerate in mature rats is characterized by the presence of hematoma from 3rd to 10th days, as well as granulation tissue from 3rd to 24th days, fibroreticular tissue, woven bone from 3rd to 45th days, and lamellar bone, from 10th to 45th days of reparative osteogenesis. Along with the well-known structures of the bone regenerate, muscle fibers have been identified in its granulation tissue. Due to the peculiarities of the structural organization of fibroreticular tissue, woven and lamellar bones and their localization in the regenerate, it is proposed to distinguish organized and unorganized layers in the first, and typical and atypical (disorganized) components in the rest. Histomorphometry was used to obtain data on the actual values of the areas of hematoma, granulation, fibroreticular tissue, woven and lamellar bones on 3rd, 10th, 15th, 24th, 45th days after fracture modeling, their percentages to the total area of the regenerate and the dynamics of their changes from one period to another. Conclusion. The histomorphometry data of the tibial regenerate on the 3rd, 10th, 15th, 24th and 45th days after surgery, as well as the revealed features of its histostructure, supplement the available information on bone fracture healing and can be used for fundamental medicine.