MORPHOLOGICAL FEATURES OF TUBULAR BONES REPARATIVE REGENERATION UNDER THE INFLUENCE OF ANTITUMOR CHEMOTHERAPEUTICS.

OBJECTIVE: The aim: Determination of morphological features of reparative regeneration of diaphysis defect of long tubular bones under the influence of antitumor chemotherapeutics in a model experiment. PATIENTS AND METHODS: Materials and methods: 96 white nonlinear rats after application of the perforated defect of the femur were administered the appropriate antitumor drug (doxorubicin, 5-fluorouracil, methotrexate) three times with an interval of 21 days. Morphological features of bone tissue formation and remodeling in the regenerate area were studied using histological and morphometric methods. RESULTS: Results: The inhibitory effect of antitumor chemotherapeutics on the formation of regenerate, expressed by slowing down the process of bone tissue differentiation was found. This is confirmed by a decrease in the area of reticulofibrous and lamellar bone tissue, chaotic arrangement and narrowing of bone trabeculae with uneven color, slow formation of bonding lines between the maternal bone and the regenerate. CONCLUSION: Conclusions: The revealed morphological features of reparative regeneration of the diaphysis defect of long tubular bones under the influence of antitumor chemotherapeutics doxorubicin, 5-fluorouracil and methotrexate in a model experiment indicate a slowing of reparative regeneration processes at all stages of recovery after injury.

STRUCTURE OF THE KNEE ARTICULAR CARTILAGE AFTER THE FEMUR AND TIBIA EXTRA-ARTICULAR INJURY.

OBJECTIVE: The aim: To study the microscopic, ultramicroscopic, and histomorphometric features of the knee articular cartilage in rats with an extra-articular injury of the femur and tibia. PATIENTS AND METHODS: Materials and methods: 60 white laboratory rats divided into three groups (I - control; II - animals with traumatic femur injury; III - animals with traumatic tibia injury) were used for the study. The light microscopy was performed by Olympus BH-2 microscope (Japan), transmission electron microscopy - by JEM-1230 microscope (Japan). SPSS software (version 17.0) was used for mathematical analysis. RESULTS: Results: The more pronounced morphological changes were observed in the articular cartilage of the proximal tibial epiphysis after mechanical tibial injury. The thickness of the articular cartilage was 27.89 % less than in the control. The chondrocyte number in the superficial zone was lower by 8.94 %, intermediate zone - by 14.23 %, and deep zone - by 21.83%, compared to control. Herewith, the histological changes were mostly detected in the intermediate and deep zones of the articular cartilage of both bones. Also, some chondrocytes had deformed nuclei, hypertrophied organelles, numerous inclusions, and residual glycogen granules. CONCLUSION: Conclusion: The extra-articular mechanical trauma of the lower limb bones leads to pathological changes in the knee articular cartilage. The structural changes include the articular cartilage thickening, the decrease in chondrocyte number, as well as chondrocyte rearrangement due to degenerative-dystrophic processes.