Excelsior es apparatus

The obtained material was fixed in neutral 10% formalin solution. The bone tissue was decalcified in an acid-free solution. Standard histologic diagnosis was performed using the Excelsior ES apparatus (Thermo Scientific, USA). After the diagnosis, paraffin blocks were made using the HistoStar embedding workstation (Thermo Scientific). 4–6 μm thick sections were obtained using the Microm HM 325 microtome (Thermo Scientific), stained with hematoxylin and eosin using the Gemini AS staining station (Thermo Scientific). For morphometric processing and creation of a video archive of the obtained material, the Leica 2500 microscope (Leica Biosystems, Germany) was used, field lens ×4, ×10, ×20, ×40, ×100, eyepiece lens ×10.

Sampling for histological examination was carried out by carefully separating muscles from bones followed by isolating bone segments 1–1.5 cm long including the bone regeneration areas. This bone material was fixated in 10% buffered formalin solution for three days and then decalcified in Trilon-V solution (Khimreaktiv, Russia). The standard histological processing was performed using an Excelsior ES apparatus (Thermo Fisher Scientific, USA). After that, paraffin blocks were prepared using a HistoStar filling station (Thermo Fisher Scientific). Sections 4–6 μm thick were obtained with the help of a Microm HM 325 microtome (Thermo Fisher Scientific) and stained with hematoxylin and eosin using a Gemini AS staining station (Thermo Fisher Scientific). Microscopic examination was carried out with a Leica DM2500 light-optical microscope (Leica Microsystems) under ×100 or ×200 magnifications.